Until recently, on-the-spot tests for alcohol were only practical
with the aid of various breath-alcohol analyzers. This
work, however, clearly demonstrates that saliva is a good alternative
biological specimen in many situations (24). The
QED is primarily intended for use as a preliminary screening
test for the presence of alcohol in the body, but quantitative test
results are also possible. The QED tubes have obvious potential
for on-site workplace testing because they offer a rapid and objective
control of postaccident alcohol involvement. The QED
device is capable of distinguishing between saliva-alcohol concentrations
of 20-40 mg/dL (0.02-0.04 g %)judging from the
results in Table I. However, note that there is a much greater
uncertainty when QED is used to estimate the venous blood- or
breath-alcohol concentrations (Table II).