T7D T7DS - Persee Analytics Inc

Transcription

U V- V I S S P E C T R O P H O T O M E T E R
U S E R
T7D
T7DS
M A N U A L
Analytical
Instruments
for
Science
Preface
Thank you for purchasing our products. To operate this instrument safeley please observe
the following precautions:
Please read the instruction manual carefully before operating the instrument.
Do not operate the instrument before understanding the operating procedures.
Pay attention to words which are emphasized in the manual, especially the safety
descriptions.
This manual is for the use of all versions of the T7D/T7DS UV-VIS Spectrophotometers.
Copyright © 2005 Persee Analytics Inc.
All rights reserved.
I
Contents
Chapter 1.
1.1
Introduction ............................................................................................................................1
Unpacking.....................................................................................................................................1
1.2
Components description ..............................................................................................................1
1.2.1
Front view ................................................................................................................................2
1.2.2
Rear view .................................................................................................................................3
1.2.3
Side view .................................................................................................................................3
1.2.4
Display .....................................................................................................................................4
1.2.5
Keypad .....................................................................................................................................5
1.2.6
Sample cell holder ...................................................................................................................6
1.3
Specifications ..................................................................................................................................8
Chapter 2.
2.1
Installation ..............................................................................................................................9
site requirement .............................................................................................................................9
2.2
Installation ....................................................................................................................................9
2.2.1
Connect the instrument to the printer.......................................................................................9
2.2.2
Connect the instrument to PC ................................................................................................10
2.3
Turning on the instrument ........................................................................................................ 11
2.4
Performance check .................................................................................................................... 12
2.4.1
Wavelength accuracy and reproducibility ..............................................................................12
2.4.2
Baseline flatness ....................................................................................................................13
Chapter 3.
3.1
Photometric measurement ....................................................................................................14
Gain access to photometric mode ............................................................................................... 14
3.2
Setting the method parameters................................................................................................... 15
3.2.1
Set photometric mode ............................................................................................................16
3.2.2
Set measuring wavelenghth ...................................................................................................16
3.2.3
Set K factor ............................................................................................................................ 18
3.2.4
Dark current correction ..........................................................................................................18
3.2.5
Quit parameters setting .......................................................................................................... 19
3.3
Sample control ............................................................................................................................. 19
3.3.1
Select sample module (changer) ............................................................................................20
3.3.2
Set sample cell number in use (Drive Cell No.) ....................................................................20
3.3.3
No.1 cell blank correction ......................................................................................................21
3.3.4
Sample cell shifting (Moving the cell changer) .....................................................................22
3.3.5
Reset to cell No.1 (Cell reset) ................................................................................................22
3.3.6
Single cell measurement ........................................................................................................22
3.3.7
Quit sample control................................................................................................................22
3.4
Auto zero (100T% correction) .................................................................................................... 22
3.5
Measurement ................................................................................................................................ 22
3.5.1
Single cell measurements.......................................................................................................22
3.5.2
Use multi-cells .......................................................................................................................23
3.6
Looking up the measurement results ......................................................................................... 24
3.7
Delete the measurement data ...................................................................................................... 24
3.8
Printout ......................................................................................................................................... 25
II
3.9
Quit measurement ....................................................................................................................... 25
3.10
Application example ................................................................................................................... 25
Chapter 4.
4.1
Spectrum scanning ............................................................................................................... 27
Gain access to spectrum mode ................................................................................................... 27
4.2
Parameters setting ...................................................................................................................... 28
4.2.1
Set photometric mode ........................................................................................................... 29
4.2.2
Setting the scanning speed .................................................................................................... 30
4.2.3
Setting the sampling interval................................................................................................. 30
4.2.4
Setting the wavelength range ................................................................................................ 31
4.2.5
Setting the ordinate range ..................................................................................................... 32
4.2.6
Light source selection ........................................................................................................... 33
4.2.7
Dark current correction ......................................................................................................... 33
4.2.8
Quit parameters setting ......................................................................................................... 34
4.3
Baseline correction ...................................................................................................................... 34
4.4
Measurement ............................................................................................................................... 34
4.5
Peak picking ................................................................................................................................ 35
4.6
Printout ...................................................................................................................................... 36
4.7
4.8
Application example ................................................................................................................. 37
Chapter 5.
5.1
Quantitative measurement ................................................................................................... 39
Gain access to quantitation mode .............................................................................................. 39
5.2
Parameters setting ...................................................................................................................... 40
5.2.1
Set measurement method ...................................................................................................... 41
5.2.2
Set measuring wavelength .................................................................................................... 41
5.2.3
Set concentration unit............................................................................................................ 43
5.2.4
Dark current correction ......................................................................................................... 43
5.2.5
Quit parameters setting ......................................................................................................... 44
5.3
Construct the calibration curve ................................................................................................. 44
5.3.1
K-Factor method ................................................................................................................... 44
5.3.2
Standards method .................................................................................................................. 46
5.4
Sample control ............................................................................................................................. 50
5.5
Auto zero ...................................................................................................................................... 50
5.6
Measurement ............................................................................................................................... 50
5.6.1
Use single cell ....................................................................................................................... 50
5.6.2
Use multi-cells ...................................................................................................................... 51
5.7
Looking up the measurement results ........................................................................................ 52
5.8
Delete the measurement data ................................................................................................... 52
5.9
Printout ...................................................................................................................................... 52
5.10
5.11
Application example ................................................................................................................. 52
Chapter 6.
DNA/Protein Analysis .......................................................................................................... 56
6.1 The principle of Protein/DNA analysis ............................................................................................ 56
III
6.1.1 Principle of using absorbance of UV light to determine protein: .................................................56
6.1.2 Principle of using absorbance of UV light to determine DNA: ....................................................56
6.1.3 Protein/DNA determination methods............................................................................................56
Gain access to DNA/Protein analysis .........................................................................................57
6.3
Parameters setting ....................................................................................................................... 59
6.3.1
Selection analysis method ......................................................................................................60
6.3.2
Dark current correction ..........................................................................................................61
6.4
Custom defined method .............................................................................................................. 61
6.4.1
Set measuring wavelength .....................................................................................................61
6.4.2
Set DNA factors .....................................................................................................................62
6.4.3
Set protein factors ..................................................................................................................63
6.4.4
Set background correction at 320nm ..................................................................................... 64
6.4.5
Set calibration factors ............................................................................................................65
6.5
Auto zero....................................................................................................................................... 66
6.6
Measurement ................................................................................................................................ 66
6.7
Look up the measurement results .............................................................................................. 66
6.8
Delete the measurement data .................................................................................................... 67
6.9
Printout ......................................................................................................................................... 67
6.10
Chapter 7.
Utilities .................................................................................................................................. 68
7.1
Gain access to utilities ................................................................................................................. 68
7.2
Set lamp changeover wavelength ................................................................................................ 68
7.3
Set spectral bandwidth ................................................................................................................ 69
7.4
Set tungsten lamp On/Off ........................................................................................................... 69
7.5
Set deuterium lamp On/Off ........................................................................................................ 70
7.6
Set control mode .......................................................................................................................... 71
7.7
Set time ......................................................................................................................................... 72
7.8
Reset system ................................................................................................................................. 72
Chapter 8.
Maintenance.......................................................................................................................... 74
8.1 Points for attention: ........................................................................................................................... 74
8.2
Daily care ...................................................................................................................................... 74
8.3
Trouble shooting and maintenance ............................................................................................ 75
Appendix 1 Light source replacement .......................................................................................................... 77
Replace the tungsten lamp ..................................................................................................................... 77
Deuterium lamp replacement .................................................................................................................79
Appendix 2 Cell holder replacement .......................................................................................................... 811
Appendix 3 Fuse replacement .................................................................................................................... 833
IV
Instruction manual
Chapter 1. Introduction
1.1 Unpacking
When unpacking, check that packing list to confirm that all the items listed are included. If any items are
missing or damaged then please contact your supplier immediately. Refer to the following table 1-1 for the
standard instrument set. But refer to the packing list for your configuration.
Table 1-1 Standard set
No.
Name
Amount
1
Main Unit
1
2
RS232 Communication Cable
1
3
Socket Screw Wrench
1
4
Instruction Manual
1
5
Quartz Cells (10mm)( pair)
1
6
Fuses for Power(2A for 220V)
2
7
Fuses for D2 Lamp(0.5A for 220V)
2
8
Power Cord
1
9
Black Block
1
10
Dust Cover
1
11
Packing List
1
12
Quick Installation Guide
1
1.2 Components description
When unpacking please ensure that the instrument is present as shown in Fig. 1.1.
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Instruction manual
Fig. 1.1 Instrument overview
1.2.1 Front view
The front view is shown as Fig. 1.2.
Fig. 1.2 Front view
Instrument cover
Front baffle of sample compartment — standard front baffle for sample compartment. It can be
replaced when using accessories requiring tubing access to the sample compartment.
Chassis — The main chassis is made from steel and this can greatly reduce any vibrations
present in the vicinity and also contributes to the excellent stability of the instrument.
Instrument label
Keypad and display — 320h240 dots high resolution LCD and 27 keystrokes.
Sample compartment cover — Open the cover to gain access to the sample compartment.
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Instruction manual
1.2.2 Rear view
The rear view is shown as Fig.1.3.
Fig. 1.3 Rear view
Light source housing coverüOpen the cover to gain access to the light source housing, here you
can replace the deuterium lamp and tungsten lamp.
Feet packingüShock proof rubber washer is used.
Printer interfaceüConnection to HP parallel inkjet printers.
RS-232 interfaceüCommunication port for a PC.
Wiring terminalüConnection to a ground wire for countires requiring this facility.
Outletü Connection to power supply: AC 220V, 50Hz.
FuseüCan be replaced (refer to “Appendix 3 fuse replacement”).
Power switch
Power labelüdescribes the power requirements.
Instrument nameplate and Serial Number
Fan
1.2.3 Side view
The instrument side view is shown in Fig.1.4. There are no other interfaces or labels except the
ventilation grills.
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Instruction manual
A: Left side view
B: Right side view
Fig. 1.4 Side view
1.2.4 Display
The LCD display on the T70 is a high resolution LCD with 320h240 dots. This displays the
measured data, spectra, method parameters, mode and prompts for operating the instrument. The
display and keypad are shown in Fig.1.5.
Fig. 1.5 Display and keypad
There are two types of menu. One is the main menu (Fig.1.6A) which appears after initialisation
and is used to select the measurement mode. The other is the operation menu (Fig.1.6B) which
displays the current working mode, measured data, spectra and user prompts information.
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Instruction manual
A: Main menu
B: Spectrum measurement menu
Fig. 1.6 Display Menu
At the top of the screen as shown in Fig 1.6B the current working mode of operation is displayed.
The column on the right of the screen displays the function keys (F1~F4). The function keys may
vary from page to page.
The center of the screen is the operating area where the measured results are displayed.
At the bottom of the screen there is the information area which informs the user about the
current status of the instrument it also allows you to enter parameters.
There are four measurement modes: photometric measurement, spectrum measurement,
quantitative determination and DNA/Protein analysis. Please refer to the following chapters for
detailed operating procedures.
1.2.5 Keypad
Altogether there are 27 soft-touch keys on the keyboard of the T70 which are divided into 4
groups. The functions of the keys are described as follows:
Fig. 1.7 Keypad
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Instruction manual
Function keys:
The function keys are used to setup the instrument parameters and are used to operate the
instrument. When one of the five function keys (F1~F5) is pressed the system executes the
corresponding operation such as setting the method parameters, deleting, setting the sample cell
positions, printing and dark current correction etc..
śDisplay Contrast adjustment point Here you can adjust the contrast of the display by using a 3˄3mm diameter˅screwdriver.
ŜNumeric keys:
These are used to input the numeric values when setting up the method parameters.
ŝEdit keys:
,
˅üüUsed to shift the cursor up and down while browsing data,
and increase and decrease values when setting the time.
ƽ Cursor keys˄
,
˅üüUsed to switch the displayed data when measuring DNA ,
and for setting the time and also for looking up the data when peak picking.
ƽ Cursor keys˄
ƽ Cancel key˄
ĀCLEā˅
üüUsed to delete entries or to cancel a certain operation.
ƽ Enter key˄
ĀENTERā˅
üüUsed to confirm and execute the current function, or to exit
the method parameters setting and to quit.
ƽ Return key
üüUsed to quit the current function and return to the previous page.
ŞOperation keys:
ƽ Auto zero key
: Used to set the ABS to zero (and transmittance to 100%). In the
will set the ABS to zero only at the
photometric mode and the quantitative mode,
performs a baseline scan across the set
current wavelength. In spectrum mode,
wavelength range.
ƽ Wavelength set key
ƽ Start/Stop key
: Used to set the current wavelength.
: Used to start or stop a measurement.
şIndicator lamp: Indicates the power supply is on.
1.2.6 Sample cell holder
The sample cell holder is configured according to the user’s requirements. The general
configurations are fixed cell holder, 8-cell changer, and 5-cell changer. We can also supply a range of
different types of sample cell holders, please refer to “chapter eight Accessories” for detailed
information.
The following figure 1.8 shows the three types of sample cell holders, which are used as the
standard configuration.
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Instruction manual
A: Fixed cell holder
B: 8-cell changer
C: 5-cell changer
Fig. 1.8 frequently used cell holders
Fixed cell holder: As shown in 1.8A, it is the most frequently used cell holder, having only
one standard cell position. It can only measure one sample at a time.
8-cell changer: As shown in 1.8B, it has eight standard cell positions and can measure up to a
maximum of 8 samples automatically.
5-cell changer: As shown in 1.8C, it has five custom defined cell positions and can measure
up to a maximum of 5 samples simultaneously. You can put the samples in standard 10mm path
length cells or use long-pathlength cells. Please refer to the 5-cell changer instruction manual for
detailed information. It also completes measurement automatically.
A: 8-cell changer
B : 5-cell changer
Fig. 1.9 Multi-cell changer
You can use different types of cell holders according to your requirements. Please refer to “Appendix
ĊThe replacement of a sample cell holder”for more information on the replacement of frequently used cell
holders.
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Instruction manual
1.3 Specifications
Split beam optics
Model
T7
T7S
Wavelength range
190nm~1100nm
Spectral bandwidth
2nm
5, 2, 1, 0.5nm (4 steps)
Wavelength display
0.1nm
Wavelength accuracy
0.3nm (with automatic wavelength correction)
Wavelength reproducibility
0.2nm
Photometric system
Double beam ratio monitoring system
Photometric accuracy
0.002Abs (0~0.5Abs)
0.004Abs (0.5~1.0Abs)
0.3%T (0~100%T)
Photometric reproducibility
0.001Abs (0~0.5Abs)
0.002Abs (0.5~1.0Abs)
0.15%T (0~100%T)
Stray light
0.3%T (220nm)
Baseline flatness
Stability
0.002Abs (190-1100nm)
0.001A/30min (2 hours warming up, 2nm bandwidth, at 500nm)
Double beam optics
Model
T7D DOUBLE BEAM
Wavelength range
T7DS DOUBLE BEAM
190nm~1100nm
Spectral bandwidth
2nm
5, 2, 1, 0.5nm (4 steps)
Wavelength display
0.1nm
Wavelength accuracy
0.3nm (with automatic wavelength correction)
Wavelength reproducibility
0.2nm
Photometric system
Double beam optical system
Photometric accuracy
0.002Abs (0~0.5Abs)
0.004Abs (0.5~1.0Abs)
0.3%T (0~100%T)
Photometric reproducibility
0.001Abs (0~0.5Abs)
0.002Abs (0.5~1.0Abs)
0.15%T (0~100%T)
Stray light
0.2%T (220nm)
Photometric Noise
0.001Abs (at 500nm, 2nm bandwidth 0Abs)
Baseline flatness
0.0015Abs (190-1100)
Stability
0.0008A/h (2 hours warming up, 2nm bandwidth, at 500nm)
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Instruction manual
Chapter 2. Installation
2.1 Site requirement
To ensure a better working quality and to prolong the service life of the instrument, install the
instrument in a place that satisfies the following requirements:
a.
Ambient temperature:
15ć~35ć
b.
Relative humidity:
less than 80%
c.
The instrument should be placed on a stable workbench, avoiding strong vibrations.
d.
Avoid a place with strong magnetic or electric fields and corrosive gases.
e.
Power requirements:
AC110V/220V f 10%, 50Hz/60Hz f 1Hz, single phase. A
regulated power supply with at least 500VA capacity is recommended. There should be a ground line
in the laboratory to ensure the instrument is well grounded.
2.2 Installation
2.2.1 Connect the instrument to the printer
All the T70 UV-VIS Spectrophotometers can be connected to HP parallel printers. The
instruments connected with PC can use any printer as long as your PC can recognize it.
The following is the installation scheme of the connection between the instrument and the printer.
Put the printer cable with 25-pin plug into the parallel interface of the instrument, and put the other
end with a 36-pin plug into the printer interface.
Connect all the cables firmly by locking the screw (if there is any) on the plugs. Plug in the
power cords of the spectrophotometer and the printer to the mains power.
Note:
1. Make sure the power supply is AC 110V/220V, 50HZ/60Hz before plugging the power cords of the
instrument and the printer. For the voltage, 10% fluctuation is allowed. The instrument can’t work normally
if the power supply is out of range. High voltage may cause damage to the instrument.
2. Do not insert or pull out the printer cable when the instrument is on, otherwise it may destroy the
instrument and the printer.
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Instruction manual
Fig. 2.1 Installation scheme
2.2.2 Connect the instrument to PC
Some of the models in the T70 UV-VIS Spectrophotometer range can be connected to a PC. The
connection scheme is shown in the following figure 2.2. Plug one end of the communication cable
with serial interface into the instrument RS232 interface (serial port). Plug the other end into the PC
RS232 interface (serial port). The two ends of the communication cable are the same.
Connect all the cables firmly by locking the screw on the plugs. Plug in the power cords of
spectrophotometer and the PC to the mains power.
Note:
1. Make sure the power supply is AC 110V/220V, 50HZ/60Hz before plugging the power cords of the
instrument and the printer. For the voltage, 10% fluctuation is allowed. The instrument can’t work
normally if the power supply is out of range. High voltage may cause damage to the instrument.
2. Do not insert or pull out the communication cable when the instrument is on, otherwise it may
destroy the instrument and PC.
Fig. 2.2 Connection scheme
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Instruction manual
When connecting to a PC, you will need to install the UVWin software. Please refer to the
software instruction manual for UVWin software operation.
2.3 Turning on the instrument
After confirming that there is nothing in the sample compartment, turn on the power switch of
the main unit and then the printer (if there is one). The instruments information will appear. Then the
initialisation page will be displayed on the LCD. The instrument starts self-checking and initialising.
This process will take about 3 minutes. After initialsation the system displays the instrument main
menu, as shown in Fig.1.6A.
Note:
If the initialisation fails, please first check whether there is a sample in the sample
compartment. Then restart the instrument. If the instrument still can’t initialise
normally, please contact your local dealer.
A: Instrument information
B: Initialization menu
Fig. 2.3 Initialisation
After the inialisation has completed you can operate the instrument. Ideally you should allow the
lamps to warm up for 15 to 30 minutes prior to use this will ensure that your data is accurate and
stable. Then you can start measurements.
Once you have finished using the instrument first turn off the instrument, then turn off the printer
power, and then turn off other appliances such as the PC.
When connecting to a PC, first switch on the power of the instrument, then the PC power. Run
the software after the computer finishes starting. If the instrument can work both in Local Control
mode and PC mode, you should select PC mode in the menu of utilities, please refer toĀ7.6 Set
control modeāthen run software.
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Instruction manual
2.4 Performance check
After installation, you need to check the performance and main specifications of the instrument.
And you should check the instrument periodically to ensure its performance meets the standard
requirements. The performance checks, as described in the following paragraphs, should be
performed after 30-minutes warm up time.
2.4.1 Wavelength accuracy and reproducibility
The wavelength accuracy should be f0.3nmˈand the wavelength reproducibility should be
0.2nm (Please refer toĀ1.4 Specificationsā). You can use two characteristic emission lines radiated by
the deuterium lamp to check the wavelengths. The detailed methods are shown below (please refer to
the software instruction manual when connected to a PC).
Make sure the spectral bandwidth isĀ2.0nmā. After initialisation, press
to set the slit width toĀ2.0nm”.
utilities, and press
to access the
Note:
It is not necessary to set the slit width if the instrument is a fixed
bandwidth instrument. Only instruments with a variable slit should be set.
Press
measurement.
to return to the main menu ˈ press
to select photometric
to access the method parameters menu. Then press the numeric keys to set the
Press
sampling interval to 0.2nm (set it to 0.1nm when connecting with a PC), set the scanning
speed to middle, wavelength range to 660-480nm, y axis to 0-100, the photometric mode to
Es, and select D2 lamp as the light source (refer to “3.2 parameters setting).
Press
Press
to return to the spectrum scanning page.
, input 6 as the gain value, and then press
to start scanning.
After scanning press
to input the threshold value (1̚100) then perform a peak pick
(if the picked peak is 0.000nm press the RETURN key. Then press F2 to input a smaller
value for the threshold and then perform the peak pick again).
Press
key to printout.
Repeat 1 three times and perform the peak pick each time. The two standard emission lines of
the deuterium lamp are 656.1 nm and 486.0 nmǄ
ǏĆ ǐ
ɋďɌ
The difference between the average value and the standard value of the three times’
measured peak is equivalent to the wavelength accuracy.
The difference between the maximum value and the minimum value of three times’
measured peak is the wavelength reproducibility.
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Instruction manual
2.4.2 Baseline flatness
Do not place any opaque object into the sample cell holder. Use an air blank to measure the
Absorbance over the full wavelength range. The method is shown as follows (refer to the software
instruction manual when connected to a PC).
ķ
Make sure the spectral bandwidth isĀ2.0nmā(refer to the first step 2.4.1).
Press
to access the menu for the photometric mode.
Press
to access the menu for setting the method parameters. Set the photometric
mode to Abs, the sampling interval to 1nm, scanning speed to middle, wavelength range to
1100̚190nm, and y axis to -0.01̚0.01 (refer to “4.2 parameters setting”).
Press
Press
Press
key to return to the menu for photometric measurement, then press
to perform a baseline correction.
to start scanning.
to printout.
Read the Absorbance. The difference between the starting point value and the maximum
deviation value over the full range is the baseline flatness (a small deviation at the wavelength lamp
change is allowed).
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Instruction manual
Chapter 3. Photometric measurement
In Photometric mode single wavelength measurements of absorbance and transmittance can be
made. K-Factor calculation and printout are possible.
3.1 Accesing the Photometric mode
From the instrument main menu, please press
to access the Photometric mode. Press
to return to the instrument main menu, as shown in Fig. 3.1:
A: Main menu
B: Photometric mode
Fig. 3.1 Accessing the photometric mode
When you exit the photometric mode you will be prompted to “Delete all the data? (If Yes: press
to return to the instruments main menu and the measured
enter. If No: press CLE.)”. Press
to return to the photometric mode and you will be prompted with
data will be lost. Press
“press START to measure” then you can continue with photometric measurements.
Note:
Please print out the measured data before returning to the instrument main menu,
otherwise the data will be lost.
The following paragraphs are an introduction to the main menu for photometric mode:
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Instruction manual
Fig. 3.2 Photometric mode
Ā PHOTO ā means photometric measurement ˗Ā 990 nm ā is the current working
wavelength˗
Ā0.000 Absāis the live Absorbance Value.
Working area: displays the detailed measurement data in a table format. It can display up to
a maximum of 9 rows of results on each screen, if this exceeds, it will display results on the
next screen.
Information area: the current information is prompting the user to press
begin measurement.
to
Time display area: time in the above picture is eight thirty four on April 15.
Display area for function keys: shows the function keys
functions are shown as follows:
ƽ
üü access to the method parameters menu;
ƽ
üü delete the measurement data;
ƽ
üü set the sample cell holder;
ƽ
üü print the measured data.
üü
. The detailed
In addition, pressing
from this menu allows you to set the wavelength and pressing
performs an auto zero at the current set wavelength.
3.2 Setting the Method Parameters
From the menu for photometric measurement, press
to gain access to the method
to return to the photometric mode menu, as shown in
parameters setting page, and press
Fig.3.3:
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Instruction manual
A: Photometric mode menu
B: Parameters setting page
Fig. 3.3 Gain access to the parameters setting page
On this page, users can set the photometric mode, wavelength and the value of factor K by
pressing the corresponding numeric keys. After you have finished setting up the parameters, press the
key to return to the previous page.
3.2.1 Set photometric mode
Press
key to set the photometric mode. There are two modes available: Abs and %T, as
is pressed.
shown in Fig. 3.4. They can be selected alternately each time when key
A: Photometric mode: Abs
B: Photometric mode: T%
Fig. 3.4 Set work mode
3.2.2 Set measuring wavelength
Press
key to set the measuring wavelength in photometric mode. A message prompts the
user to input the wavelength, as shown in Fig.3.5:
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Instruction manual
A: Parameters setting page in photometric mode
B: Wavelength setting page
Fig. 3.5 Setting the wavelength in photometric mode (1)
At the bottom of this page, enter the desired wavelength value by pressing the numeric keys
̣
and decimal point
. The
key is used to clear the previous entry. Press
key to confirm the wavelength entry and quit. If nothing is to be entered press the
key to quit this page and return to the photometric menu.
Note:
The input wavelength value should be an integer value or with one digit precision.
The range is from 190 to 1100. If the input value exceeds 6 digits (including decimal
or exceeds the range, the system will delete what has been entered automatically
point)
and you should start a new entry again.
You also can press
from the photometric menu (as shown in Fig. 3.2) to set the
working wavelength in the photometric mode, as shown in Fig. 3.6:
A: Photometric mode menu
B: Wavelength setting menu
Fig. 3.6 Wavelength setting page in photometric mode (2)
At the bottom of this page, enter the desired wavelength value by pressing the numeric keys
̣
and decimal point
. The
key to confirm the numeric entry and quit. If nothing is to be entered, press the
key
to quit this page and return to the photometric menu.
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Instruction manual
Note:
The input wavelength value should be an integer value or one with digit precision. The
range is from 190 to 1100. If the input value exceeds 6 digits (including decimal point) or
exceeds the range,
the system will delete what has been entered automatically and you will
need to start a new entry again.
3.2.3 Set K factor
Press
key to set K factor in the photometric mode, as shown in Fig.3.7:
A: Parameters setting
B: K factor setting page
Fig. 3.7 K factor setting page
̣
,
At the bottom of this page, enter K factor value by pressing the numeric keys
and
. The
key
decimal point
to confirm the numeric entry and return to the parameters setting page in photometric mode. If
key to quit this page and return to the method parameters
nothing is to be entered press the
setting page in photometric mode.
Note:
The input K factor should be an integer value or a decimal fraction. The range is from
190 to 1100. If the input value exceeds 6 digits (including decimal point and negative sign)
or exceeds the range, the system will delete what has been entered automatically and you
should start a new entry again.
3.2.4 Dark current correction
Dark current correction is performed to ensure the accuracy of the measured results. You
should perform a dark current correction when environmental and instrument conditions change,
such as temperature variations and relocation of the instrument. Also when you measure highly
absorbing samples, it is advisable to perform a dark current correction before you start taking
measurements. The procedure is shown as follows:
18
Instruction manual
A: Parameters setting page in photometric mode
B: Dark current correction
Fig. 3.8 Dark current correction
Press
to perform dark current correction from the parameters setting page. It will display
“system busy”. Then about 10 seconds later, it will prompt the user with the message “Please select
Item”, this means that the dark current correction has finished, as shown in Fig.3.8. 3.2.5 Quit parameters setting
Press
key to quit the method parameters setting and return to the main menu for
photometric measurement.
3.3 Sample control For sample holders you can select the preferred sample changer (fixed cell holder, 5-cell changer
and 8-cell changer are available). If you select 8-cell changer or 5-cell changer, you can set cell
number, move cell and cell reset etc.
to gain access to the sample control menu in the case of photometric measurement,
Press
as shown in Fig. 3.9:
A: Photometric measurement menu
B: Sample control menu
e.g. 3.9 Set sample control
19
Instruction manual
In the case of sample control, press the corresponding numeric keys to set cell holders. Then,
to return to photometric mode menu.
press
3.3.1 Select sample module (changer)
Press
key to select sample module. There are three types available, fixed cell-holder,
key.
5-cell holder and 8-cell holder. You can alternate between them each time by pressing the
Fig. 3.10 Select sample module
3.3.2 Set sample cell number in use (Drive Cell No.)
This parameter is only available for the 5-cell changer and the 8-cell changer. For sample
key to gain access to set the cell number in use, as shown in Fig.3-11:
module, press the
A: Sample cell setting page
B: set sample cell number
20
Instruction manual
Fig. 3.11 Set cell number in use
ü
At the bottom of this page, enter the sample cell number by pressing the numeric keys
. Press
key to clear off the previous entry. Press
key to confirm the numeric entry
to return to the set up parameters page for sample
and quit. If nothing is to be entered, press
control. A 1-digit figure entry is allowed. The range is from 1 to 8. If you enter a number which
exceeds the range, the system will delete the entry. You should enter a number again.
Note:
Only one integer is accepted. When the sample module is 8-cell changer, the range is
1-8; when the sample module is 5-cell changer, the range is 1-5. If the entered figure
exceeds
the range, the system will delete what has been entered. You should start a new
entry.
During the measurement procedure each sample cell position is measured one by one. The serial
number sequence of sample cells is expressed by n-1, n-2, …
3.3.3 No.1 cell blank correction
You can set position 1 on the Cell Changer to perform a blank correction to No.l cell (only
key, it
available for 5-cell changer and 8-cell changer). Each time the user presses the
alternates between “yes” and “no” as shown in Fig.3.12.
Fig. 3.12 Set No.1 cell blank correction
This parameter is used to set No. 1 cell to perform a blank correction.
21
Instruction manual
3.3.4 Sample cell shifting (Moving the cell changer)
This option is only available for the 5-cell changer and 8-cell changer. Press the
key to move the cell holder to the sasmple position.
The numeric value displayed relates to the current cell number. Each time you press the
key, it will move to the next cell position. The cell changer resets to No.1 cell once you
have reached the maximum cell number. The maximum cell number for the 5-cell changer is
five, and the maximum cell number for the 8-cell changer is eight.
3.3.5 Reset to cell No.1 (Cell reset)
This option is only available for the 5-cell changer and 8-cell changer. Press the
key to reset the cell changer to sample cell No.1.
3.3.6 Single cell measurement
If you set the “Cell Number” to 1, you can choose any one of the cell positions on the
multi-cell changer as the measuring cell by moving the cell changer to the preferred
position as described in 3.3.4. Then, the measurement will be made only on the chosen cell.
3.3.7 Quit sample control
To quit the sample control press the
photometric mode as shown in Fig. 3.3.
key to return to the main menu for
3.4 Auto zero (100T% correction)
In photometric mode, press the
key to set the Absorbance to zero at the
current wavelength. Remember to insert your blank before you perform the correction.
3.5 Measurement
3.5.1 Single cell Measurements
Single cell measurements include the fixed cell measurement and use of one cell position
on a multi-cell changer to measure (refer to 3.3.6 single cell measurement).
First set up the measurement parameters and sample cell parameters then perform an
key to measure
auto zero. Place your sample into the sample cell, then press the
key, it will re-measure the sample. The
its Abs or T%. Each time you press the
measurement results will be displayed as shown in Fig. 3.13 (take Abs for example):
22
Instruction manual
Fig. 3.13 Single cell measurement results
ĀNo.āin the table refers to serial No. of the samples set by the user.Ā2 -1āin the table
refers to the second measurement result of No.1 cell (if use multi-cell changer, it refers to
current sample cell in use); “Abs” refers to absorbance value;ĀK*Absārefers to the value of
measurement multiplied by K-Factor. The K factor in the above table is 10.
3.5.2 Use of multi-cells
First set up the measurement parameters and sample cell parameters. The measurement
procedures will vary with the settings of No. 1 cell blank.
When Reagent Blank Correction in Cell No. 1 is set to “NO”
When Reagent Blank Correction in Cell No. 1 is set to “NO”, you need to perform an
auto zero on cell No.1. After auto zero, put the samples into sample cells, then press
key to start measurement. And then the measured values will be calculated, saved
and displayed on the LCD one by one.
When Reagent Blank Correction in Cell No. 1 (c3.5.3) is set to “YES”
When Reagent Blank Correction in Cell No. 1 is set to “YES”, you do not need to
perform an auto zero. The system will first measure the set N samples. Then the measured
values of samples No.2~No.N will be deducted (corrected) by that of the blank in sample cell
No. 1 following the formula below. The corrected results will be recorded, calculated and
displayed on LCD one by one.
ƽ Absorbanceφ
$EVRUEDQFHRI&HOO1RQ WKHPHDVXUHPHQWYDOXHRI&HOO1RQ
㸫$EVRI&HOO1R
ĂĂĂĂ˄3-1˅
ƽ Transmittance: 7KHWUDQVPLWWDQFHRIVDPSOH1RQ PHDVXUHGYDOXHRIVDPSOH1RQ
PHDVXUHGYDOXHRIVDPSOH1REODQN
ĂĂĂĂ˄3-2˅
The measurement results of multi-cells are shown as Fig.3.14. ĀNo.āin the table refers
to sample serial number set by the user.Ā2 -3āin the table refers to the second measurement
23
Instruction manual
result of No.3 cell (if you use a multi-cell changer, it refers to current sample cell in use);
“Abs” refers to absorbance value;ĀK*Absārefers to the value of measurement multiplied by
K-Factor. The K factor in the above table is 10.
Fig. 3.14 Multi-cell measurement results
3.6 Looking up the measurement results
After measurement, you can look at the measurement results by pressing the cursor keys
and
.
3.7 Delete the measurement data
You can press the
key to delete the measured data. You will be prompted with the
to confirm and
information “Delete all the data? (YES: ENTER, NO: CE).” Press
key to cancel the operation, and you will be prompted to
delete all the data. Press
“Press START to measure”, and then you can continue to take more readings.
Fig. 3.15 Delete measurement data
24
Instruction manual
Please remember to print the measured data before deleting your results.
3.8 Printout
After measurement, you can press the
key to printout your results. You will be
prompted with the information “Printer is ready? (YES: ENTER, NO: CE)”, as shown in
Fig.3.16:
Fig. 3.16 Data printout
key to print the measured data. If your printer
If your printer connects well, press
to cancel the operation. If your printer is not ready and you have
is not ready, press
key, the system will prompt you with “System busy…” and you can press
pressed
to exit this selection.
Please refer to “Chapter 2 Installation” for printer installation. If your printer does not
work normally please refer to “Chapter 9 Daily Care and Maintenance”.
3.9 Quit measurement
Press
to quit measurement. It will prompt the user with the information
to return to the main menu of
“Delete all the data? (YES: Enter; NO: CE)”. Press
instrument.
3.10
Application example
Vitamin B1, also known as thiamin, helps fuel your body by converting blood sugar into
energy. It helps to keep your mucous membranes healthy and it is essential for the nervous
system, cardiovascular and muscular function. The Spectrophotometric method tests the
absorbance value of Vitamin B1 at the wavelength of 400nm. If the absorbance value is not
25
Instruction manual
greater than 0.020, it means the tested product has passed and qualified.
The procedure for using the T70 UV-VIS Spectrophotometer to test Vitamin B1 is as
follows:
Dissolve Vitamin B1 1g in 10ml-deionized water; then, put Vitamin B1 and
de-ionized water into cells separately.
Turn on T70 UV-VIS Spectrophotometer. After 60 minutes’ preheat time, press
to gain access to photometric mode menu.
Refer to “3.2 Parameters setting”, set photometric mode to Abs, the measuring
wavelength to 400nm, and the factor to the default 1.000.
For the first measurement, put the black block (an accessory which is supplied with
to perform a dark current
the instrument) into the sample cell, and then press
to return to
correction (refer to 3.2.4 dark current correction). Then, press
the main menu of photometric measurement.
to gain access to sample control. Refer to “3.3 Sample control”. After
Press
to return to the main menu of photometric measurement.
setup, press
Measurement:

If the “Cell No.” is set to 1, first put the reference cell (de-ionized water) into the
key to
sample cell holder, close the sample compartment, and then press
auto zero. The absorbance value displayed on the photometric mode menu should
be 0.000 Abs. After correction, put the sample cell (Vitamin B1) instead of
reference cell into the sample cell holder. Close the sample compartment. Then
key to start measurement. The measured results will be displayed
press
in the table automatically.

If the “Cell No.” is not set to 1 and you do not wish to perform a No.1 cell blank
correction, first put the reference cell into the No.1 cell, close the sample
key to perform an auto zero. Then place the
compartment, and press
to measure the samples. The
sample cells into the cell holder, press
measurement results will be displayed in the table.

If the “Cell No.” is not set to 1 and you wish to perform a No.1 cell blank
correction, put the reference cell into the No.1 Cell, then place the samples into the
key, the system will automatically calculate the
other cells, press
absorbance values of the samples. The measured results will be displayed in the
table. The value of the reference No.1 cell should be 0.000Abs.
To delete or print the measurement results after measurement (please refer to 3.5
measurement).
26
Instruction manual
Chapter 4. Spectrum scanning
This mode allows the user to measure the absorbance, transmittance and energy of the
measured sample (Es), and energy of reference (Er) in a certain wavelength range.
4.1 Gain access to spectrum mode
From the main menu, press the
key to access the spectrum mode and press
to return to the main menu, as shown in Fig. 4.1:
A: Main menu
B: Spectrum mode
Fig. 4.1 Gain access to spectrum mode
When you exit the spectrum mode, the system will prompt the user with “Delete all the
data? (YES: ENTER, NO: CE)”.
If you press
ˈyou will return to the main menu and the measured data will be lost.
you will return to the photometric mode and you will be prompted to
If you press
“press START to measure”, then you can continue to perform a scan.
Note:
Please print out the measured data before returning to the main menu, otherwise,
the data will be lost.
The following paragraphs give an introduction to the main menu functions within
spectrum mode:
27
Instruction manual
Fig. 4.2 Main menu of spectrum mode
“SPECTRUM” means that the current working modeis spectrum scanning;Ā990
nmārefers to the current working wavelength˗ andĀ0.000 Absārefers to the live
absorbance value.
Working area: the spectrum is shown as a graph. The abscissa refers to the
wavelength value and the ordinate refers to absorbance value (it also can refer to
T%, Es or Er according to the photometric mode you choose from the menu).
This area displays promps and information: the displayed information is prompting
to begin scanning the sample.
the user to press the
Time and date display area: the time in the above diagram is eight thirty four on
April 15 th.
Display area for the function keys: shows the function keys
detailed functions are shown as follows:
ƽ
üü access to the method parameters menu;
ƽ
üü peak picking;
ƽ
üü spectrum printout;
ƽ
üü wavelength correction
üü
. The
In addition, you can press
from this menu and set the current wavelength and
you can perform a baseline correction.
by pressing
4.2 Parameters setting
From the main menu for spectrum mode, please press
to access the method
to return to the main menu of spectrum mode, as
parameters menu page. Press
shown in Fig. 4.3:
28
Instruction manual
A: Main menu of spectrum mode
B: Parameters setting
Fig. 4.3 Method parameters menu page
From this page, users can set the photometric mode, scanning speed, scanning
wavelength range, ordinate full scale range and sampling interval by pressing the
corresponding numeric keys. After you have finished setting up the method parameters, press
key to return to the previous page.
the
4.2.1 Set photometric mode
Press
key to set photometric mode. Four modes are available: Abs, Er, Es and %T
key.
to alternate between each option press the
Fig. 4.4 set photometric mode
29
Instruction manual
4.2.2 Setting the scanning speed
The options are Fast, Middle and Slow. You can choose Fast if you just want to get
general information about peaks in a wide range. You can choose Slow if you want to get
accurate and reliable peak location and peak values in a small range.
Press
key to set the scanning speed Fast, Middle or Slow in turn, as shown in Fig.
4.5:
Fig. 4.5 Set scanning speed
4.2.3 Setting the sampling interval
Press the
key to set the sampling data interval. You have 6 choices: 5nm, 2nm,
key is pressed in
1nm, 0.5nm, 0.2nm or 0.1nm they can be selected in turn when the
succession.
30
Instruction manual
Fig. 4.6 Set sampling data interval
Note:
A maximum of 910 data points can be stored for one spectrum. The product of
sampling interval and wavelength range should be less than 910. If this is exceeded
you will prompted with the information “WL range does not match interval”. You
should then choose a different data interval.
4.2.4 Setting the wavelength range
Press
key from the method parameters menu to set the wavelength range, as
shown in Fig. 4.7:
Fig. 4.7 Setting the wavelength range
31
Instruction manual
At the bottom of this page enter the start wavelength by pressing the numeric keys
̣
and decimal point
. The
key is used to clear the previous entry.
key to confirm. If the value you entered meets the requirements the system will
Press
key to confirm. The system will accept
prompt you to input the stop wavelength. Press
the wavelength range you have entered and return to the method parameters menu page. If
key to quit.
Note:
The input wavelength value should be an integer value or with one digit
precision. The range is from 190 to 1100. If the input value exceeds 6 digits (including
decimal point) or exceeds the range, the system will delete what has been entered
automatically and you should start a new entry again.
The default wavelength range is from long wavelength to short wavelength, and
the instrument will scan from long wavelength to short wavelength. If the start
wavelength you entered is shorter than end wavelength, the instrument will take the
long wavelength as the start wavelength and the short wavelength as the end
wavelength.
4.2.5 Setting the ordinate range
Press
key on the parameters setting page in the case of spectrum scanning to set
ordinate range, as shown in Fig. 4.8:
Fig. 4.8 Setting the ordinate range
32
Instruction manual
At the bottom of this page, the system prompts the user to set the lower limit of the
üü
and
to enter the desired
ordinate axis. Press the numeric keys
Key is used to clear the previous entry. After setting the lower limit, the system
value.
key to confirm the numeric entry and quit.
prompts the user to set the upper limit. Press
key to quit. A 5-digit figure entry is allowed.
If nothing is to be entered press the
The range is from –9999~9999. If the figure entered exceeds five digits the system will delete
what has been entered. You should enter it again.
Note:
The system accepts integral and decimal, the range of which is –999-999. If the
input value exceeds 7 digits (including decimal point and negative sign) or exceeds the
range, the system will delete what has been entered automatically and you should start
a new entry again.
The system remembers the ordinate ranges you set for the different photometric modes.
For example if you set the ordinate range for Abs to be -0.01̚0.01 and then you change
to %T, and set its ordinate range to be 0̚100, when you change the photometric mode back
to Abs again the ordinate range will still be -0.01̚0.01.
4.2.6 Light source selection
For the photometric modes of Es and Er you can also select the light source you want to
use to peform the spectrum scan.
You should make sure that the photometric mode is set to Es or Er. Then press the
key from the spectrum scan parameters menu page to select the light source. Each time you
key the light source will alternate between tungsten lamp and deuterium
press the
lamp as shown in Fig. 4.9:
Fig. 4.9 Light source selection
Dark current correction is performed to ensure the accuracy of the measured results. You
should perform a dark current correction when environmental factors change. This might
include temperature variations in the laboratory or a change in location or when measuring
highly absorbing samples. The operational procedures are shown as follows:
33
Instruction manual
A: Parameters setting page
Press
to perform a dark current correction from the spectrum scan parameters
menu page. The message “system busy…” will be displayed. After about 10 seconds the user
will be a prompted to “Please select Item”, meaning the dark current correction has finished
as shown in Fig.4.10.
4.2.8 Quit parameters setting
Press
key on parameters setting page to return to the main menu of spectrum
scanning, as shown in Fig. 4.3.
4.3 Baseline correction
From the main menu of spectrum scanning, press the
key to start a baseline
correction at the set wavelength range. Before starting a baseline correction, place the blank
key can be pressed to stop the baseline
sample into the sample compartment. The
correction operation. If you change the wavelength range a new baseline should be
performed.
4.4 Measurement
First set up the method parameters and perform a baseline correction, then put the
to start scanning. The measured
sample cell into the cell holder and press
spectrum will be displayed as a graph.
Note:
For “Es͇and͆Er͇the system will prompt you to input the gain when pressing
key. The range is 1-15. Input your preferred gain and press
to
to delete the entry.
start measurement. Press
When the system prompts you with the information “Press START to measure” it means
that the measurement has finished as shown in Fig. 4.11 (take Abs for example):
34
Instruction manual
Fig. 4.11 Spectrum scanning page
The abscissa in the graph above relates to the wavelength range from 1000nm to 190nm,
and the ordinate range is displaying the absorbance value from –0.010 to 0.010.
4.5 Peak picking
Once the scanning has completed you can perform peak picking by selecting
from the main menu of spectrum scanning as shown in Fig. 4.12:
Fig. 4.12 Peak picking operation page
At the bottom of this page you can enter the threshold value for picking the peaks or
üü
,
and
. Press
valleys by pressing the numeric keys
key to confirm. If nothing is to be entered, press the
to clear the previous entry. Press
key to quit.
Note:
The threshold value, shown as percentage, is also the minimum detection limit. The system can
detect whether the spectrum is beyond the setup threshold value.
The system can accept integral and decimal as threshold value, the range of which is 1-100. If
the input value exceeds 4 digits (including decimal point and negative sign) or exceeds the range, the
system will delete what has been entered automatically and you should start a new entry again.
35
Instruction manual
After the threshold value entered, the system will start peak-picking calculation and the
calculated result will be displayed on the screen, as shown in Fig. 4.13.
and
to check the peaks.
After peak picking, you can move cursor keys
to print the result, and press
to return to the main menu of spectrum
Press
mode.
If the threshold value in the information indication area is 0.000nm 0.000, it means the
key and press
key to input a smaller
system haven’t detected the peak, press
threshold value, and then perform peak picking again.
Fig. 4.13 Peak picking
4.6 Printout
After measurement, you can press
key to printout. Please refer to “3.8 Printout”.
If there are no measurement results, pressing
key is inoperative.
Note:
Sometimes the spectrum displayed in the LCD is different from the printed
one, because the resolution of the printer is higher than that of the LCD. The
spectrum data points displayed is less than that of the printed. But the peak values
are the same.
Press
to quit measurement. It will prompt the user with the information
to return to the main menu of
“Delete all the data? (YES: Enter; NO: CE)”. Press
36
Instruction manual
instrument.
4.8 Application example
Vitamin B12 has characteristic absorption peak at 361nm, which the operators always
concern when they perform spectrum scanning of vitamin B12. We will take vitamin B12 for
example to show the user how to perform spectrum scanning.
The procedures of using T70 UV-VIS Spectrophotometer to measure the absorption peak
of Vitamin B12 are shown as follows:
Mix standard vitamin B12 injection with de-ionized water in a proportion of 1:10 to
get 10ml dilution solution. Then pour the dilution solution and de-ionized water
into two quartz cells separately (de-ionized water as reference).
Turn on T70 UV-VIS Spectrophotometer. After 60 minutes’ preheat time, press
to gain access to spectrum mode menu (refer to 4.1 gain access to spectrum
mode).
key to gain access to parameters setting page. Set the photometric
Press
key, set the scan speed to Middle by pressing
mode to Abs by pressing
, set the wavelength range to
key, set the sample interval to 1nm by pressing
, and set the ordinate range to 0.000-2.000 by
220nm-660nm by pressing
(please refer to “4.2 Parameters setting” for the detailed
pressing
information).
Put the black block into the sample cell on the sample optical path (only this cell
on the parameters setting page to perform dark
can be used now). Press
to return to photometric mode
current correction. After correction, press
menu.
Take out of the black block, put the quartz cell with de-ionized water into the
to
sample cell holder, cover the sample compartment, then press
perform baseline correction. The indication area will display “scanning baseline…”.
key during correction, the correction data will be lost and
If you press
you should start baseline correction again.
After baseline correction, the indication area will display “Press START to
measure”. Take out of the de-ionized water cell, and put the sample cell into the cell
key to perform
holder, cover the sample compartment, then press
spectrum scanning. The indication area will display “scanning baseline…” and the
again to stop measurement and the
spectrum will be displayed. Press
results will be lost.
After measurement, it will prompt the user with the information “Press START to
to set threshold value, and then perform peak picking. If
measure”. Press
peak value is not available (indication area displays 0.000nm 0.000Abs), press
37
Instruction manual
to return and then set up threshold value again (for detailed information
about peak picking, please refer to “4.5 peak picking”).
Press
etc.).
to print measurement results (spectra, peaks values and wavelength
38
Instruction manual
Chapter 5. Quantitative measurement
This mode allows the user to perform single-wavelength quantitative determinations and
to construct standard curves. The K-Factor Method and Calibration Curve Method are
available.
5.1 Gain access to quantitation mode
From the main menu, press
key to access the quantitation mode, press
to return to the main menu, as shown in Fig. 5.1:
A: Main menu
B: Quantitation mode menu
Fig. 5.1 Gain access to quantitation mode
When you exit the quantitation mode, the system will prompt the user with the
information “Delete all the data? (YES: ENTER, NO: CE)”.
Pressing
will return to the main menu and the measured data will be lost. Pressing
will return to the quantitation mode and a prompt will display with the information
“press START to measure” then you can continue with the quant measurements.
Note:
Please print out the measured data before returning to the main menu,
otherwise, the data will be lost.
The following paragraphs are an introduction to the quantitation mode menu:
39
Instruction manual
Fig. 5.2 Main menu of quantitative measurement
ķ “QUANT” means the current working mode is the quantitative measurement, Ā990
nmārefers to the current working wavelength˗ andĀ0.000 Absārefers to the live
display of the real time absorbance value.
ĸ
Working area: the measured results are shown in the table. It can display a
maximum of 9 rows of measuremed values each time. Ĺ
Information display area: the current information is prompting the user to press
to begin measurement.
ĺ
Time display area: time in the above picture is eight thirty four on April 15.
Ļ
Display area for the function keys: show the function keys
ƽ
üü Gain access to method parameters set up page;
ƽ
üü Delete measurement data;
ƽ
üü Set up of sample control;
ƽ
üü Printout
üü
. The
In addition you can also press
to set the working wavelength and you can press
to perform a baseline correction.
5.2 Parameters setting
For quantitative measurement press
to access the method parameters set up page.
to return to the main menu for quantitative measurement as shown in Fig. 5.3:
Press
40
Instruction manual
A: Main menufor quantitation mode
B: Method parameters set up page
Fig. 5.3 Gain access to parameters setting page
The quant method parameters menu allows the user to set the working mode, measuring
wavelength, and concentration by pressing the corresponding numeric keys. Press
to return to the previous page.
5.2.1 Set measurement method
K-Factor Method and Standards Method are available. Please refer to “5.3 construct
calibration curve” for constructing calibration curves.
key to set the working method for quantitative
From quant method page press
is pressed each time,
measurement. The two methods can be selected alternately when
as shown in Fig. 5.4:
Fig. 5.4 Set measurement method
Press
to set the measuring wavelength as shown in Fig. 5.5:
41
Instruction manual
Fig. 5.5 Set measuring wavelength ()
At the bottom of this page, enter the desired wavelength value by pressing the numeric
̣
and decimal point
. The
key is used to clear the previous
keys
key to confirm the numeric entry and quit. If nothing is to be entered,
entry. Press
key to quit this page and return to the quant method page.
press
Note:
The range is from 190 to 1100. If the input value exceeds 6 digits (including decimal
point) or exceeds the range, the system will delete what has been entered automatically
and you should start a new entry again.
You also can press
from the the main menu for quantitation mode (as shown in
Fig. 5.2) to set the working wavelength as shown in Fig. 5.6:
Fig. 5.6 Set measuring wavelength ()
At the bottom of this page, enter the desired wavelength value by pressing the numeric
̣
and decimal point
. The
key is used to clear the previous
keys
key to confirm the numeric entry and quit. If nothing is to be entered,
entry. Press
key to quit this page and return to the quant menu page.
press
Note:
The input wavelength value should be an integer value or with one digit precision. The range is
from 190 to 1100. If the input value exceeds 6 digits (including decimal point) or exceeds the range, the
system will delete what has been entered automatically and you should start a new entry again.
42
Instruction manual
5.2.3 Set concentration unit
There are 9 choices available: “none”, “mg/L”, “%”, “mol/mL”, “ug/L”, “g/L”,
“mg/mL”, “ng/mL”, “mol/L”.
key to set concentration unit. Each time you press
key, the
Press
concentration unit will change between “none”, “mg/L”, “%”, “mol/mL”, “ug/L”, “g/L”,
“mg/mL”, “ng/mL”, and “mol/L”, as shown in Fig. 5.7.
Fig. 5.7 Set the concentration unit
A dark current correction is performed to ensure the accuracy of your data. You should
perform a dark current correction when environment changes occur such as temperature
variations and changes in location for the instrument, also when you measure highly
absorbing samples. The operation procedures are shown as follows:
43
Instruction manual
A: Parameters setting page
Press
to perform a dark current correction from the parameters setting page. A
message will be displayed “system busy…”. After about 10 seconds you will be prompted
with the message “Please select Item” this means that the dark current correction has finished
as shown in Fig.5.8.
5.2.5 Quit parameters setting
From the parameters setting page for quantitative measurement press
quit the menu as shown in Fig. 5.3.
key to
5.3 Constructing a calibration curve
Before you construct a calibration curve you should set the parameters.
5.3.1 K-Factor method
The K-Factor method is used to perform quantitative measurements if you know the
calibration curve. You can construct a calibration curve by inputting the factor and the
intercept.
First make sure that you have selected the measurement method to be “K-Factor”. Press
key from the quantitation parameters setting page to access the parameters setting page.
key to return to the previous page as shown in Fig. 5.9.
Press
44
Instruction manual
Fig. 5.9 Parameters setting page for the K-Factor method
The displayed formula is “Conc˙K*Abs+B”. Please set the Slope K and Intercept B by
pressing
and
key separately.
Set the slope for the calibration curve
From the parameters setting page for K-Factor method, press
as shown in Fig. 5.10.
key to set slope K,
Fig. 5.10 Set the slope of K-Factor method
At the bottom of this page, enter factor K by pressing the numeric keys
̣
.
key is used to clear the entry. Press
key to confirm. If nothing is to be
The
key to return to parameters setting page.
entered, press
Note:
input value exceeds 7 digits (including decimal point and negative sign) or exceeds the
the system will delete what has been entered automatically and you should start a
range,
new entry again.
Set the intercept of calibration curve
From the parameters setting page for K-Factor method, press
intercept B as shown in Fig. 5.11.
45
key to set the
Instruction manual
Fig. 5.11 Set the intercept of K-Factor method
At the bottom of this page enter the intercept B by pressing the numeric keys
̣
. The
key to confirm. If nothing is to
be entered press
Note:
input
value exceeds 7 digits (including decimal point and negative sign) or exceeds the
range, the system will delete what has been entered automatically and you should start a
entry again.
new
5.3.2 Standards method
The Standards method refers to the method of constructing a calibration curve by using
the standards concentration values and absorbance values.
First ensure that you have selected the measurement mode to be “Standard”. Press
from the quantitation parameters setting page to access the parameters setting page for the
Standards method as shown in Fig. 5.9.
Fig. 5.12 Parameters setting for the Standards method
From the parameters setting page press
to set the number of standards, press
to set the concentration and absorbance values of a specific standard sample. Press
key to use cell 1 to measure the standards absorbance values. After measurement, press
key to construct and display the calibration curve.
46
Instruction manual
Set standards number
Press
key to set standards number, as shown in Fig. 5.13:
Fig. 5.13 Set standard number
At the bottom of this page, enter standard number by pressing the numeric keys
̣
. The
key to confirm. If nothing is to
be entered press
Note:
The system accepts integral㸪the range of which is 1-10. If the input value exceeds 7
digits (including decimal point and negative sign) or exceeds the range, the system will
what has been entered automatically and you should start a new entry again.
delete
Set concentration value and absorbance value
From the parameters setting page for the standards method, press
key to set the
specific standard sample, as shown in 5.14. At the bottom of this page, enter standard No.
̣
. The
by pressing the numeric keys
key to confirm. If the entered number is eligible, the system will prompt the user to
key to skip
input the standard concentration. If nothing is to be entered press the
it. The default standard number will be used (as displayed on the screen).
At the bottom of this page enter the concentration value by pressing the numeric keys
̣
. The
key to confirm. If the
entered value is eligible, the system will prompt the user to input the standard absorbance
key to skip it. The default concentration
value. If nothing is to be entered, press
will be used (displayed on the screen).
At the bottom of this page, enter the absorbance value by pressing the numeric keys
̣
. The
key is used to clear off the entry. Press
key to confirm. If the
entered value is eligible, the system will prompt the user with the information “Please select
key to quit the standards setting page. The
item”. If nothing is to be entered, press
default absorbance value will be used (displayed on the screen).
47
Instruction manual
Fig. 5.14 Set the standards concentration value and absorbance value
Note:
The system accepts integral as the Std. No.㸪the range of which is 1 to Std. Number. If
the input value exceeds 7 digits (including decimal point and negative sign) or exceeds
the range, the system will delete what has been entered automatically and you should
start a new entry again.
The system accepts integral and decimal as the concentration and absorbance, the
range of which is –999-999. If the input value exceeds 7 digits (including decimal point
and negative sign) or exceeds the range, the system will delete what has been entered
automatically and you should start a new entry again.
Measure the standards absorbance
The user should perform a blank correction before measuring the standards absorbance.
Put the blank into the No. 1 cell, and then press
key to perform auto zero.
After auto zero, press
key in the parameters setting page to measure the
absorbance, as shown in Fig. 5.15. Put the standards into the No. 1 sample cell, and then press
key to measure the current standards absorbance. After measurement, the result
will be displayed and the system will prompt the user with the information “Please Select
Item”.
48
Instruction manual
Fig. 5.15 Measure the standards absorbance
Standards absorbance measurement is used when the user knows the standards
concentration but does not know the standards absorbance. First select the standard No., then
to skip the absorbance value
input the standards concentration value and then press
setup to measure the standards absorbance.
Construct calibration curve
key on the parameters setting page of standards
After the standards setup, press
method to construct the calibration curve, as shown in Fig. 5.16.
Fig. 5.16 Calibration curve display
The abscissa in the above figure is the absorbance value and the ordinate is the
concentration value. The calibration curve equation will be displayed at the bottom of the
key to printout (Please refer to 3.8 Printout).
page. Press
Press
key on the calibration curve display page to return to the parameters
setting page. The calibration curve equation will be displayed under the “Curve Parameter”.
Note:
If the standards setup does not meet the requirements of constructing a calibration
curve, the system will prompt the user with “ Data Range Error, Retry.” Press
key then to reset the parameters.
49
Instruction manual
Quit calibration curve parameters setting
Press
setting page.
key to quit calibration curve parameter setting, and return to parameter
5.4 Sample control
From the main menu for quantitative measurement as shown in Fig. 5.2, press
key to access the sample control page. The sample control operation is the same as that of the
photometric measurement. Please refer to “3.3 Sample control”.
5.5 Auto zero
From the main menu for quantitative measurement press the
key to set the
Absorbance to zero at the current measuring wavelength. Before starting auto zero place the
blank into the cell.
5.6 Measurement
5.6.1 Use single cell
The single cell measurement includes fixed cell measurement and using one cell position
on the multi-cell changer to take measurements (refer to 3.3.6 single cell measurement).
First set up measurement parameters and sample cell parameters then construct a
calibration curve. Perform auto zero. Place the sample into the sample cell and press the
key to measure its Absorbance value. Each time you press the
key it
will re-measure the sample. The measurement results will be displayed as shown in Fig. 5.17.
Fig. 5.17 Single cell measurement results
50
Instruction manual
ĀNo.āIn the table refers to serial number of the samples set by the user. Ā2 -1āin the
table refers to the second measurement result of No.1 cell (if a multi-cell changer is being
used it refers to the current sample cell in use); “Abs” refers to absorbance value;ĀConc”
refers to the concentration value calculated by the calibration curve. 5.6.2 Using multi-cells
First set up measurement parameters and sample cell parameters, and then construct a
calibration curve. The measurement procedures will vary with the settings of No. 1 cell blank.
When Reagent Blank Correction in Cell No. 1 is set to “NO”
When Reagent Blank Correction in Cell No. 1 is set to “NO”, you need to perform an
auto zero on position cell No.1. After auto zeroing put the samples into the sample cells, then
key to start measurements. The measured values will be calculated, saved
press
and displayed on the LCD one by one.
When Reagent Blank Correction in Cell No. 1 (c3.5.3) is set to “YES”
When Reagent Blank Correction in Cell No. 1 is set to “YES”, you do not need to
perform auto zero. You need to put the blank sample into Cell position No.1, and then put the
samples into the other cell positions. The system will first measure the set N samples. Then
the measured values of samples No.2~No.N will be deducted (corrected) by that of the blank
in sample cell No. 1 following the formula below. The corrected results will be recorded,
calculated and displayed on the LCD one by one.
ƽ Absorbanceφ
$EVRUEDQFHRI&HOO1RQ WKHPHDVXUHPHQWYDOXHRI&HOO1RQ㸫$EVRI&HOO
1R
The measurement results using the multi-cell holder is shown as Fig.5.18. ĀNo.āin the
table refers to the serial number of the samples set by the user. Ā2 -3āin the table refers to
the second measurement result of No.3 cell (if use multi-cell changer, it refers to current
sample cell in use); “Abs” refers to absorbance value; “Conc” refers to the concentration
value calculated by the calibration curve. The following picture shows the results of using
three cells measuring twice.
Fig. 5.18 Multi-cell measurement results
51
Instruction manual
5.7 Looking up the measurement results
After measurement you can look up the results by pressing cursor keys
.
and
After measurement press the
delete the measurement data”.
key to delete measured results. Please refer to “3.7
5.9 Printout
“3.8 Printout”.
key to print out the measured results. Please refer to
Press
to quit measurement. You will be prompted to “Delete all the data? (YES:
to return to the main menu of instrument.
Enter; NO: Clear)”. Press
5.11 Application example
Determination of nitrite in food is an important item in food safety and inspection.
The quantitation mode of the T70 series spectrophotometers can be used to determine
the nitrite content and the procedures are shown as follows:
Reagent preparation:
Distilled water should be used for preparing standard solutions.
Ammonium chloride buffer: Pipette 500ml distilled water, 20.0ml hydrochloric acid into
a 1L volumetric flask. Shake up. Then pipette 50ml ammonium chloride into the volumetric
flask. Dilute to the mark with distilled water. If necessary, adjust the buffer PH to 9.6-9.7 with
dilute hydrochloric acid and dilute ammonium hydroxide.
ƽ Zinc sulfate solution (0.42̉̋̈ˋ˨): dilute 120g zinc sulfate (˶̊˯˫4g˓ˤ2
52
Instruction manual
˫) to 1000ml with distilled water.
ƽ Sodium hydroxide solution (20g/L): Dilute 20g sodium hydroxide to 1L with
distilled water.
ƽ Sulfuric acid solution: Dilute 10g sulfuric acid into the mixed solution of 700ml
water and 300 ml glacial acetic acid. Put the solution into a brown bottle, and then
shake up. Preserve it at room temperature.
ƽ ˪ ˉ ˍ ˉ Naphthyethylenediamine
(1g/L): Dilute 0.1g ˪ ˉ ˍ ˉ
Naphthyethylenediamine to 100ml with 6% acetic acid solution. Put it into a brown
bottle, and shake it up, then place it into a refrigerator for a week.
ƽ Chromomeric agent: Mix ˪ˉˍˉNaphthyethylenediamine solution (1g/L) with
sulfuric acid solution equally.
ƽ Sodium nitrite standard solution: Put 250.0mg sodium nitrite, dried in a silica gel
dryer for over 24 hours, into a 500ml volumetric flask. Dissolve it with water (about
200ml). Add 200ml ammonium chloride buffer to it, and then dilute it to the mark
with water. Swirl to mix. Preserve the solution at 4ć, avoiding light. Each milliliter
of the solution equals 500̃ sodium nitrite.
ƽ Sodium nitrite standard: Before measurement, pipette 1.0ml standard solution into a
100ml volumetric flask, and then dilute it to the mark with water. Each milliliter of
the solution is equal to 5.0̃ sodium nitrite.
Sample processing:
Place the sample 10.00g (foodstuff 5g) into the breaker to break. Mix it with 70ml water
and 12ml sodium hydroxide. Adjust the sample PH to 8 with sodium hydroxide (20g/L). And
then place the sample solution into a 200ml volumetric flask. Mix it with 10ml zinc sulfate. If
it doesn’t produce a white deposit add sodium hydroxide 2-5ml to mix it up. Place the sample
into a water bath, heat for 10mins and then cool it to room temperature. Add water to the
mark. Filter the sample solution with filter paper after half an hour. Discard the primary filter
solution 20ml, and collect the filter solution.
Switch on the instrument
Turn on the T70 UV-VIS Spectrophotometer. After 30mins warm-up, press
main menu to access the quantitation mode.
from
Parameters setting
Please refer to “5.2 Parameters setting”, set the measurement mode to “Standards
method” and working wavelength to 550nm.
Standard preparation
Pipette the prepared sodium nitrite standard 0.10ml, 0.20ml, 0.40ml, 0.6.ml, 0.80ml, and
1.00ml (equal to sodium nitrite 2.5Ϥg, 5Ϥg, 10Ϥg, 15Ϥg, 20Ϥg and 25Ϥg) into 25ml
colorimetric tubes with stoppers. Then add 4.5ml ammonium chloride buffer, 2.5ml 60%
53
Instruction manual
acetic acid solution, and 5.0ml chromomeric agent into the tubes respectively. Dilute them
with water to the mark. Place the prepared standard samples into the dark for 25 minutes.
Place the different concentration standards into 1cm quartz cells respectively. And then
number the cells 1-6.
ļ
Standards setup
key to access the menu
From the method page for quantitative measurement press
key to change the standard number to 6.
for setting up the standards method. Press
to perform
Place the quartz cell with distilled water into the sample cell and press
an auto zero.
key to input the standards number, sample
From the standards method page, press
to skip absorbance entry. Then place the numbered sodium
concentration, and press
key and
key. The Abs value displayed is
nitrite into the cell No.1, press
the current sodium nitrite Abs.
Construct the calibration curve
From the standards method page press
key to construct a calibration curve, as
shown in Fig. 5.19. If the instrument displays “Data Range Error, Retry”, press the
key to return to the standards method page to reset the standard samples.
Fig. 5.19 Calibration curve
Measurement
Pipette 10ml filter solution into a 25ml colorimetric tube with a stopper. Then perform
measurement (refer to 5.6 measurement). Calculate the nitrite concentration by the measured
absorbance value and the standard curve.
Ŀ
Result analysis
After measurement, the nitrite content is calculated as 35.63mg/kg by the following
formula.
54
Instruction manual
A u1000
ĂĂĂĂĂĂĂĂĂĂĂ˄˅
V2
m u u 1000
V1
X ̾̾nitrite content㸪 mg / kg 㸹
X
m —sample weight㸪 g 㸹
A ̾̾nitrite weight of the filter solution in use㸪 Pg ;
V2 ̾̾the total filter solution volume㸪 mL 㸹
V1 ̾̾the volume of filter solution in use㸪 mL .
55
Instruction manual
Chapter 6. DNA/Protein Analysis
This mode allows the user to perform DNA/Protein analysis. There are two pre-set
methods and a custom defined method available.
6.1 The principles of Protein/DNA analysis
6.1.1 Principles of using the absorbance of UV light to determine
protein:
Proteins are bio-polymers there fundamental unit is the Amino Acid, there are 20 standard
Amino Acids and they are connected together by peptide bonds. Amino Acids that have
aromatic groups in their structures are Histidine, Phenylalanine, Tryptophan and Tyrosine.
The conjugated doublebond included in the tryptophan, phenylalanine, and tyrosine
absorb UV light. The absorbance values are related to the concentration of the three kinds of
amino acid. Peptide bonds also absorb UV light so the absorbance value of protein solution at
238nm is as a result of the peptide bond which is then directly related to the protein
concentration.
6.1.2 Principle of using absorbance of UV light to determine
DNA:
There are two types of nucleic acids, DNA - DeoxyRibonucleic Acid and RNA RiboNucleic Acid. The Nucleic acids are polymers; i.e., strings of similar molecules strung
together. The fundamental unit is a nucleotide and the polymer is a polynucleotide. A
nucleoside is a base + sugar and a nucleotide is base + sugar + phosphate. The five bases of
Adenine, Guanine, Cytosine, Thymine and Uracil do absorb in the UV. The high absorbance
is due to, double bonds inside aromatic rings, lone pairs on nitrogen atoms and Oxygen
double bonds. They have the maximum absorbance value at 260nm.
6.1.3 Protein/DNA determination methods
Absorption method at 280nm and 260nm
DNA & RNA absorb UV light intensely. Its absorbance ability is 10 times as intense as
protein at 280nm. The absorption of DNA & RNA at 260nm is more intense. The extinction
coefficient at 260nm is twice as much as that at 280nm. But for protein, the absorption value
at 280nm is larger than that at 260nm.
Because the protein absorption value and DNA & RNA absorption values are different,
we can judge the ratio of protein and DNA & RNA, for example:
ƽ Pure protein absorbance ratio: A280/A260 | 1.8
ƽ Mixed solution of protein and DNA & RNA:
56
A280/A260 | 1.8̚0.5
Instruction manual
ƽ Pure DNA & RNA absorbance ratio: A280/A260 | 0.5
Method:
As for the mixed solution of protein and DNA, we can determine their concentration
values by measuring their absorption values at the wavelength of 260nm and 280nm. The
formulas are shown as below:
Protein concentration 㸻 1552A280㸫757.3A260
DNA concentration 㸻 62.9A260㸫36.0A280
(ug/ml) ĂĂĂĂ˄6-1˅
ǏĆ1ǐ
(ug/ml)
ĂĂĂ˄6-2˅
ɋ*1ɌNote:
1. The coefficients need to be amended according to different situations.
2.The method is easily interfered, such as the NaCL and the solution with
conjugated doublebond.
ĸ
Absorption method at 230nm and 260nm
The peptide bond of protein has its maximum absorption value at 238nm, and we take
A230 as an approximate value. DNA&RNA also has intense absorption at 230nm. So we can
determine A230 and A260 with the fixed solution of protein and DNA.
Method:
We can determine the concentration values of protein and DNA by measuring their
absorption values at the wavelength of 230nm and 260nm. The formulas are shown below:
Protein concentration 㸻 183.0A230㸫75.8A260
DNA concentration 㸻 49.1A260㸫3.48A230
(ug/ml)……………...˄6-3˅
(ug/ml)………………….˄6-4˅
The coefficients above need to be amended according to different situations.
Comparing with absorption method at 280nm and 260nm, the absorption method at
230nm and 260nm is more accurate. But it is more easily interfered.
There is no absorbance at the wavelength of 320nm, so background correction at 320nm
can be preformed.
6.2
Gain access to DNA/Protein analysis
From the instrument main menu press
key to select the DNA/Protein mode. The
main menu for quantitative measurement will be displayed as shown in Fig. 6.1, press
to return to the instrument main menu.
57
Instruction manual
A: Instrument main menu
B: Main menu of DNA/Protein analysis
Fig. 6.1 Gain access to DNA/Protein analysis
When you exit the DNA/Protein analysis mode, the system will prompt the user with the
information “Delete all the data? (YES: ENTER, NO: CLE)”
If you press
you will return to the main menu and the measurement data will be
you will return to the main menu for DNA/Protein analysis and be
lost. If you press
rompted to “press START to measure”, then you can continue to the DNA/Protein analysis
page.
Note:
Please print out the measurement data before returning to the main menu, otherwise,
the data will be lost.
The following paragraphs introduce the main menu for DNA/Protein analysis:
Fig. 6.2 Main menu for DNA/Protein analysis
ķ ĀDNA/Protāmeans that you are currently on the DNA/Protein analysis page.
Ā260nm” and “230nm” refers to current working wavelengths˗ 58
Instruction manual
ĸ Working area: Measurement results are shown in the table and can display a
maximum of 9 rows of measurement results each time. Ĺ Information display area: The current information is prompting the user to press
to begin measurement.
ĺ Time display area: Time in the above picture is eight thirty four on April 15.
Ļ Display area for the function keys: shows the function keys
ƽ
üü Access to parameters setting page;
ƽ
üü Delete measurement data;
ƽ
üü Set sample control;
ƽ
üü Printout
üü
. The
In addition, pressing
from this menu will perform a baseline correction. Press
key and
key to alternate between A1, A2, DNA concentration, and protein
concentration as shown in Fig. 6.3:
Fig. 6.3 Results display of DNA/Protein analysis
6.3 Parameters setting From the main menu of DNA/Protein analysis press
to access the parameters
to return to the main menu for DNA/Protein analysis as shown
setting page. Press
in Fig.6.4:
59
Instruction manual
Fig. 6.4 Parameters setting page
From the method menu page for DNA/Protein analysis, the user can select either the
preset methods or the custom defined method. The user also can perform a dark current
correction from this page.
6.3.1 Selecting the analysis method
Press
key and
key from the parameters setting page to select between
method 1, method 2 and a custom defined method as shown in Fig. 6.5:
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Instruction manual
Fig. 6.5 Select DNA/Protein analysis method
When the user selects method 1 or method 2, the parameters are displayed and the user is
not allowed to amend them. When the user selects custom defined method, the user can input
the preferred parameters.
Dark current correction is performed to ensure accuracy of the measurement results.
You should perform a dark current correction when the environmental changes occur, such as
temperature variations and change of location of the instrument. Also when you measure
highly absorbing samples it is recommended that you perform a dark current correction. The
operational procedures are shown as follows:
A: parameters setting page
Press
to perform a dark current correction from the parameters setting. A prompt
will display the message “system busy…” After about 10 seconds you will be prompted to
“Please select Item”, this means that the dark current correction has completed as shown in
Fig.6.6.
6.4 Custom defined method
From the parameters setting page select “Custom” to gain access to the custom defined
method.
From the custom defined method, press
shown in Fig. 6.7:
61
key to set the working wavelength as
Instruction manual
Fig. 6.7 Set wavelengths
At the bottom of this page, enter the first wavelength value by pressing the numeric keys
̣
and decimal point
. The
key to confirm the numeric entry. The system will prompt the user to input the
Press
key to confirm the entry. If
second wavelength after entering the first one. Press
key to skip this and the system will adopt the
current setting.
Note:
The range is from 190 to 1100. If the input value exceeds 6 digits (including decimal point)
or exceeds the range, the system will delete what has been entered automatically and you
should start a new entry again.
6.4.2 Set DNA factors
6.8:
62
to set the DNA factors, as shown in Fig.
Instruction manual
Fig. 6.8 DNA factors setting
At the bottom of this page, enter the first DNA factor by pressing the numeric keys
̣
and decimal point
. The
Press
key to confirm the entry and quit.
other protein factor after entering the first one. Press
key to and the system will adopt the current
If nothing is to be entered press the
setting.
Note:
The input protein factors should be integers or decimals. The range is from -9999 to
9999. If the input value exceeds 7 digits (including decimal point) or exceeds the range,
the system will delete what has been entered automatically and you should start a new
entry again.
6.4.3 Set protein factors
6.9:
63
to set protein factors, as shown in Fig.
Instruction manual
Fig. 6.9 Protein factors setting
At the bottom of this page, enter the first protein factor by pressing the numeric keys
̣
and decimal point
. The
key is used to clear the preceding entry.
Press
key to confirm the entry and quit.
other protein factor after entering the first one. Press
key and the system will adopt the current setting.
If nothing is to be entered, press
Note:
The input protein factors should be integers or decimals. The range is from -9999
to 9999. If the input value exceeds 7 digits (including decimal point) or exceeds the
range, the system will delete what has been entered automatically and you should start
a new entry again.
6.4.4 Set background correction at 320nm
key to set background correction at
320nm. Two choices are available for this item: YES and NO, which can be selected by
key is pressed, as shown in Fig. 6.10:
alternating between the two options each time
64
Instruction manual
Fig. 6.10 Background correction at 320nm
6.4.5 Set calibration factors
shown in Fig. 6.11:
key to set the calibration factors, as
Fig. 6.11 Set calibration factors
At the bottom of this page, enter the calibration factors by pressing the numeric keys
̣
and decimal point
. The
key is used to clear the preceding entry.
key to confirm the numeric entry. The system will display the factors and return
Press
to the parameters setting page if the entered value meets the requirements. If nothing is to be
key to adopt the current setting.
entered, press
Note:
The input calibration factors should be integers or decimals. The range is from -999
to 999. If the input value exceeds 7 digits (including decimal point) or exceeds the range,
entry again.
65
Instruction manual
6.5 Auto zero
From the main menu for DNA/Protein analysis press the
key to set the
Absorbance to zero at the current measuring wavelength. Before starting auto zeroing, put the
blank sample into the cell.
6.6 Measurement
Only one cell can be used for DNA/Protein analysis (No.1 cell is used if a multi-cell
key
holder is installed). From the main menu for DNA/Protein analysis press the
it re-measures the sample and
to start the measurement. Each time you press
displays the results as shown in Fig. 6.12:
Fig. 6.12 Results display
ĀNo.āin the table refers to the serial number of the samples set by the user. Ā2āin the
table refers to the result of second measurement; “A1/A2” refers to the absorption ratio of the
two calibration wavelengths; ĀA1ā and ĀA2ārefer to the absorption values of two
key and
key to display A1, A2, DNA
calibration wavelengths. Press
concentration and protein concentration. For detailed information refer to “6.7 Look up the
measurement results”. 6.7 Look up the measurement results
After measurement, you can look up the measurement results by pressing cursor keys
and
.
The default display is A1 and A2, and the user can press
key and
key to
alternate the display between A1, A2 and DNA concentration and protein concentration, as
shown in Fig. 6.12:
66
Instruction manual
After measurement press
“3.7 Delete the measurement data”.
key to delete the measurement results. Please refer to
6.9 Printout
key to print out the measurement results including
A1, A2, DNA concentration and protein concentration. Please refer to “3.8 Printout”.
6.10
Quit measurement
Press the
key to quit measurement. You will be prompted with the information
to return to the instrument main
“Delete all the data? (YES: Enter; NO: Clear)”. Press
menu.
67
Instruction manual
Chapter 7. Utilities
This mode allows the user to set the operating conditions such as lamp changeover
wavelength, spectral bandwidth, tungsten lamp On/Off, deuterium lamp On/Off and
wavelength calibration.
7.1 Gain access to utilities
From the instrument main menu press the
key to access the utilities mode and
key to return to the instrument main menu as shown in Fig. 7-1:
press the
Fig. 7.1 Gain access to utilities mode
7.2 Set lamp changeover wavelength
From the main menu for utilities press
wavelength as shown in Fig. 7-2.
key to set the lamp changeover
Fig. 7.2 Set lamp changeover wavelength
At the bottom of this page, enter the preferred wavelength by pressing the numeric keys
̣
and decimal point
. The
key to confirm the numeric entry and quit. If nothing is to be entered press the
Press
68
Instruction manual
key to return to the main menu for utilities.
Note:
The input wavelength values should be integers or decimals. The range is from 390
to 330. If the input value exceeds 6 digits (including decimal point) or exceeds the range,
entry again.
7.3 Setting the spectral bandwidth
Press
key to set the spectral bandwidth of the instrument. Four options are
key is pressed each
available: 2.0, 5.0, 0.5, 1.0nm. They can be selected in turn when
time as shown in Fig. 7.3:
Fig. 7.3 Setting the spectral bandwidth
7.4 Setting the tungsten lamp On/Off
Press the
key to access the tungsten lamp on/off function. On and Off can be
key is pressed each time as shown in Fig. 7.4:
changed in turn when
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Instruction manual
Fig. 7.4 Setting the tungsten lamp On/Off
7.5 Setting the deuterium lamp On/Off
Press
key to access the deuterium lamp on/off function. On and Off can be
key is pressed each time as shown in Fig. 7.5:
changed in turn when the
Fig. 7.5 Setting the deuterium lamp On/Off
Note:
When the user turns on the deuterium lamp the system will display “System busy”.
When the message appears “Please select item”, the deuterium lamp has been ignited.
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Instruction manual
7.6 Set control mode
Press the
you press the
key to change control mode from PC mode to MCU mode. Each time
key you can alternate between the two options as shown in Fig. 7.6:
Fig. 7.6 Set control mode
MCU means the instrument is operating in the MCU (local control) mode. When you
choose PC mode the system will quit the utilities and restart. The system will prompt the user
with the information “ Waiting, press START to return”.
Fig. 7.7 Waiting for PC mode
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Instruction manual
7.7 Set time
Press the
key from the utilities menu page to set the time as shown in Fig. 7.8:
Fig. 7.8 Setting the Time
At the bottom of the screen it will display the current date. The time in the above picture
key and
key to increase or decrease the
is 19:49 on April 20 2005. Press
key and
key to move the cursor. After you have finished
numeric values. Press
key to return to the utilities main menu. Once you have
setting the time press the
edited the time and date you should quit the utilities mode to check the new settings.
7.8 Reset system
Press
from the main menu for utilities mode to reset all of the instruments
parameters to its original deafault setup. A message will be displayed “System busy…”.
About three seconds later you will be prompted to “Please Select Item”, now the parameters
have been reset with the original default settings.
The original setup parameters are shown in Tab 7-1.
Note:
This series of instruments can record the system parameters. The instrument will
adopt the parameters the user set last time even if the power is turned off.
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Instruction manual
Table 7-1 Original setup parameters
Photometric measurement
Description
Parameter Name
Parameter value
Photometric mode
Abs
Measuring wavelength
260.0nm
Coefficient
10
Spectrum scanning
Description
Parameter Name
Parameter value
Photometric mode
Es
Scanning speed
Fast
Sampling interval
1.0
Wavelength range
1000.0
200.0
Photometric mode: Abs
Ordinate range
0.00
1.00
Photometric mode: Tˁ, Er, Es
Ordinate range
0.00
100.00
Light source
Deuterium lamp
Quantitative measurement
Description
Parameter Name
Parameter value
Measurement method
Standards method
Measuring wavelength
260.0nm
Concentration unit
mg/L
DNA/Protein analysis
Description
Parameters can’t be changed
Parameter Name
Method
Parameter value
1
Sample control
Description
Parameter Name
Parameter value
Sample module
8-cell changer
Drive cell No.
1
Cell No.1 blank
No
Move cell
1
Utilities
Description
Parameter Name
Lamp changeover wavelength
Parameter value
359.0nm
Spectral bandwidth
2.0nm
Tungsten lamp
On
Deuterium lamp
On
Control mode
MCU
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Instruction manual
Chapter 8. Maintenance
The T70 UV-VIS Spectrophotometer is a precision instrument. Careful assembling and
final testing have been performed in the factory. Appropriate routine attention and
maintenance will not only ensure the reliability and stability of the instrument but also extend
its operating lifetime.
8.1 Points for attention:
ƽ Good environmental conditions should be provided according to the requirements in
SectionĀ2.1 Site requirement”
ƽ The instruments leave the factory fully optimised to offer excellent performance on
arrival at their destination. Users should not try to adjust the optical components by
themselves nor dismantle parts from the instrument. Pay special attention not to touch
and damage the surfaces of the optics or to wipe the surfaces carelessly.
8.2
Daily care
ƽ Always check to see if there are any sample spillages in the sample compartment after
each measurement. The sample compartment should be cleaned frequently to avoid
corrosion and damage to optical system.
ƽ The instrument should be covered with the anti-dust cover provided with the instrument.
Silica-gel bags can be placed in the sample compartment and the light source housing to
keep the instrument dry. But be sure to take the bags out before switching on the
instrument.
ƽ During daily operation and storage, the LCD display and keyboard should be handled
with care in order to prevent damage from scratches, water, dust and corrosion.
ƽ Periodically check the performance of the instrument. If anything abnormal occurs,
contact the seller or the manufacturer immediately.
ƽ If the instrument is not to be used for a long period of time, pay attention to
environmental conditions such as temperature and humidity and periodically replace the
silica-gel bags. It is recommended to turn on the instrument once a month.
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Instruction manual
8.3
Trouble shooting and maintenance
The instrument begins to initialise after turning it on as shown in Fig. 9.1. The system
gives status information after each operation has completed. If no problems are detected it
displays “OK”. If there is a problem detected it displays “Err” (Error) and asks whether the
initialisation should continue or not. The user will know the status of the instrument once the
initialization finishes.
Fig. 8.1 Initialisation
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Instruction manual
Table 8-1
Phenomenom
The instrument does not
operate at all, after the
power is turned on.
Spectrum can not be
printed out.
Causes
A) Power cable is not
securely connected;
B) Fuse has blown;
C) Circuit failure.
A) Printer failure;
B) CPU failure.
C) The connection cable
is loose
Initialisation abnormality:
1) ROM check
A) ROM failure;
2)
Wavelength origin;
3)
Multi-cell origin;
4)
Slit origin;
5)
Filter origin;
6)
W lamp energy;
7)
D2 lamp energy;
8) Wavelength check
Noise abnormality
A) Abnormality of WL
origin ;
A) Abnormality of
multi-cell holder drive
origin;
A) Slit mechanism
failure
A) Filter mechanism
failure;
A) Opaque object in the
sample compartment;
B) W lamp is not lit
sample compartment;
B) D2 lamp is not lit;
sample compartment;
B) Wrong positioning of
D2 lamp.
A) Light source ageing;
B) Wrong position of the
sample compartment;
C) Low voltage / strong
magnetic field;
D) Receiver ageing ;
E) Preamplifier board
failure;
F) Abnormality of AD
converter.
Diagnosis
A) Check the power cable;
B) Check the fuse;
C) Check the instrument.
A) Check printer;
B) Check CPU board.
C) Check the connection
cable
A) Switch on power again to
check;
check;
A) Shift cell holder to check;
B) Loose mechanical
connection;
check;
check;
A) Open the sample
compartment;
B) Open the light source
housing;
A) Open the sample
compartment;
housing;
C) Remove the cover of
instrument;
A) Open the sample
compartment;
housing.
A) Measure in Energy mode;
B) Observe at 550nm;
C) Check voltage/source of
magnetic field;
D) Measure in Energy mode;
E) Check the preamplifier
board;
F) Check the drive board.
76
Remedy
A) Connect it securely;
B) Replace the fuse (2A);
C) Contact our service
personnel.
A)-B): Contact our service
personnel.
C) Connect the connection
cable securely;
A) Contact our service
personnel;
personnel;
A) Remove the obstacle;
B) Tighten the connecting
mechanism;
personnel;
personnel;
A) Remove the opaque
object;
B) Replace the W lamp ;
object;
B) Replace the D2 lamp;
C) Replace the fuse of D2
lamp;
object;
B) Reposition the D2
lamp.
A) Replace the light
source;
B) Reposition the sample
compartment;
C) Add voltage stabilizer
/eliminate interference;
D) Contact our service
personnel;
E) Contact our service
personnel;
F) Contact our service
personnel.
Instruction manual
Appendix 1 Light source replacement
Replacing the tungsten lamp
The tungsten lamp is plugged into a socket and protected by a plastic sleeve holder. It is
well adjusted before delivery. If you need to replace the tungsten lamp please observe the
following procedures to replace it.
Fig. 9.1 Tungsten lamp set
Open the light source housing cover. Push upwards where the arrow points in Fig.
10, and then remove the light source cover.
Fig. 9.2 Open the light source house cover
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Instruction manual
ĸ Loosen the two holding screws on the W lamp socket and remove the W lamp
holder, as shown in Fig. Fig. 9.3 Loosen the two holding screws
Ĺ
Replace with a new W lamp holder. Clean the surface of the W lamp with a clean
cloth soaked with alcohol. Insert the W lamp holder into the W lamp socket in the
light source house and tighten the two holding screws.
Fig. 9.4 The filament direction
ĺ If the performance of the instrument changes greatly after replacing the lamp, the
height of the W lamp should be adjusted. (The horizontal position of the W lamp is
adjusted automatically when the self-test is performed upon switching on the
power.). First remove the W lamp holder, loosen the setscrews on the W lamp
holder with a watch screwdriver and adjust the height of the W lamp. The distance
between the center of the filament and the bottom should be 40mm according to the
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Instruction manual
design requirements. But it can be adjusted slightly. And then tighten the set screws
and insert the W lamp holder into the socket. Deuterium lamp replacement
The D2 lamp is plugged into the D2 lamp socket. To replace the D2 lamp insert a new
lamp directly and securely into the socket. The procedure is shown as follows:
Open the light source house.
ĸ
Remove the deuterium lamp. Fig; 9.5 Remove the deuterium lamp
Clean the surface of the D2 lamp with a clean cloth soaked with alcohol. Insert the
D2 lamp into its socket. The bulge part of the deuterium lamp and the dent of the
holder should be rightly overlapped (the light beam window should face the
convergent lens), as shown in Fig. 10.6.
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Instruction manual
Fig. 9.6 Insert the deuterium lamp
Slightly sway the deuterium lamp and install it securely.
Note:
1. The light source and light source housing are considerably hot during operation.
Therefore be sure to turn off the power to the instrument so as to cool down the light
source sufficiently before replacing it.
2. The convergent lens should be covered with a paper bag to avoid being
contaminated by fingers.
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Instruction manual
Appendix 2 Cell holder replacement
This appendix describes how to replace the cell holder. Replacing the single cell holder
with an 8-cell changer is also similar to the method for replacing with a 5-cell changer and
solid sample cell holder etc.
Open the sample compartment, and remove the front baffle, as shown in Fig. 11.1.
Fig. 10.1 Remove the front baffle
Loosen the two holding screws by using a plus screwdriver and remove the solid
sample cell holder.
Fig. 10.2 Remove the solid sample cell holder
Place the plug of the 8-cell changer into the socket on the pedestal of the sample
compartment.
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Instruction manual
Position the 8-cell changer, fasten the two holding screws, install the front baffle,
and cover the sample compartment, as shown in Fig. 10.3.
Fig. 10.3 Installation of the 8-cell holder
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Instruction manual
Appendix 3 Fuse replacement
This chapter introduces the user how to replace the fuse. If you suspect the fuse has
blown please replace it according to the following procedures.
Switch off the instrument.
Remove the fuse holder using a big plain screwdriver, as shown in Fig. 12.1.
Fig. 11.1 Remove the fuse holder
Remove the old fuse, and replace it with a new one. And then install the fuse holder.
The fuse replacement has finished.
Fig. 11.2 Replacing the fuse
Note:
Please select the same fuse as the old one when when replacing it.
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Persee Analytics Inc.
Address:7270 Popham Place, Solon, OH44139, United States
Contact:Sean Cao
Title:Sales and Marketing Director
E-mail:[email protected]
Tel:(440) 591 9268
Web: www.perseena.com