view this paper - ICADTS International Council on Alcohol, Drugs

Containers for Breath Samples for
Alcohol Analysis
W. KALOW, G. H. W. LUCAS and J. D. McCOLL
Department of Pharmacology,
This communication is concerned
w ith an experience gained during the
recent study in Toronto on Alcohol
and Road Traffic, which involved the
collection and the analysis for alcohol
of approxim ately 2,500 breath samples
taken from drivers of m otor cars.
Since roughly 80% of th e samples
w ere furnished voluntarily on the
request of a Police Officer by drivers
not involved in th a t accident (“nonaccident drivers”) b u t stopped at
random near the scene of the motor
car accident in question, the method
of sampling was devised to minimize
any inconvenience to “non-accident
d riv ers” and to provide adequate
protection against the loss of alcohol
from the breath sample container.
Since breath samples w ere to be
collected from four or more “non­
accident drivers” for each “accident
d riv er”, it was im perative to collect
samples quickly; furtherm ore, it is
evident th a t o n -the-spot analysis of
so m any samples was impractical.
The procedure adopted was to collect
all breath samples as quickly as pos­
sible a t the scene of the accident, to
num ber and record them, and to
re tu rn them to the laboratory for
analysis in a H arger D runkom eter
or a G reenberg Alcometer.
A few experim ents w ere conducted
w ith ru b b er balloons as containers
University of Toronto
for gas samples containing alcohol
vapour introduced by bubbling air
at room tem perature through a solu­
tion of know n alcohol content. These
experim ents soon proved th a t the loss
of alcohol was so rapid from - the
ru b b er bags as to ren d er them useless
for the procedure as planned. A fter
o n e-q u arter of an hour only one-half
of the original concentration rem ained,
w hether the sample was high or low
in alcohol. Following sim ilar trials
w ith other containers made from
other materials, it became apparent
th a t the loss of alcohol from gas
samples enclosed in polyethylene bags
was sufficiently low as to ren d er these
suitable
containers.
Consequently
such bags w ere employed for breath
samples.
*Polyethylene bags are sold in large
quantities as containers for vegetables,
meats, etc. They are thus cheap and
in regular supply. The bags used
w ere 5" x 3Vi" x 12%". The open
end of the bag was folded around a
plastic m outhpiece and affixed to it
w ith a small ru bber band. The m outh­
piece was of plexiglas which could
be sterilized and could be stoppered
by a small cork. The bags th u s p re ­
pared would hold about two litres of
air.
^Supplied by Haugh-Gordon Ltd.,
1162 D upont St., Toronto 4.
137
We tested these containers for vary ­
ing tim e intervals up to 3 hours and
40 m inutes w ith initial alcohol con­
centrations corresponding to blood
levels of 0.06, 0.09 and 0.10%. The
ra te of loss of alcohol from these
containers was such th a t approxi­
m ately one-half of the original am ount
rem ained a t the end of four hours.
F u rth e r investigations are being made
on these containers to determ ine more
specifically the loss of alcohol per
hour from gaseous m ixtures.
These bags w ere easy to inflate and
w ere not under pressure w hen filled,
a condition which minimized the loss
of gases from them . It was necessary,
however, since the gas was not under
pressure, to feed samples from them
into th e H arger D runkom eter by use
of a vacuum pum p device. This con­
sisted of a w ater suction pum p fu r­
nished w ith a piece of ru b b e r tubing
which was attached to the low er end
of th e volum etric cylinder; a glass
T-piece was inserted into this rubber
tube, th e open end of which was
fitted w ith a short piece of rubber
tubing th a t could be closed by a
screw clamp, thus perm itting a fine
regulation of the vacuum . Samples
for analysis in the G reenberg Alcom eter could be forced into the Alcom eter by squeezing th e bag. It is
w orthy of m ention th a t this vacuum
system was used to advantage in
adjusting the gasometers quickly for
a subsequent analysis.
The resu lt of this investigation
showed th a t the loss of alcohol vapour
from ru b b er balloons can interfere
seriously w ith alcohol tests unless the
ru b b er balloons ax*e tested im m e­
diately after th e sampling. A test in
the H arger D runkom eter can be con­
138
ducted in two ways; the decolorization
of perm anganate is correlated either
w ith a volume of air or w ith an
am ount of carbon dioxide. It m ust
be pointed out th a t all our tests were
based on th e correlation w ith a volume
of air. No attem pt has been made
in this study to learn w hether or not
the loss of alcohol would interfere
w ith a test based on a simultaneous
determ ination of carbon dioxide.
W hile polyethylene bags w ere used
to advantage, it is not alleged that
they make the best containers for
b reath samples; fu rth er research may
discover m aterials th a t are more
suitable for containers.