P. Jaouen et al., DYNAMIC POLLUTED ATMOSPHERE GENERATOR AT LOW PPBV LEVELS FOR VALIDATING VOC SAMPLING METHODS, Environmental science & technology, 29(11), 1995, pp. 2718-2724
A reconstituted VOC atmosphere generator in the ppbv-pptv range is pre
sented. Designed for dynamic mode operation, this generator continuous
ly monitors the generated atmospheric concentration by UV spectrophoto
metry using an optical tracer, styrene, which is a strong UV absorber.
In the ppbv range, the tracer is detected using a multipath White cel
l with signal recovery by a lock-in amplifier. The VOCs are injected i
n the liquid phase. By diluting these compounds in the liquid phase, i
t is also possible to generate atmospheres in the pptv range. The beha
vior of the tracer reflects the behavior of all the other compounds in
jected simultaneously. Generator operation and characteristics of the
dynamic atmosphere were checked by chromatography. Among other applica
tions, this apparatus can be used to investigate various sampling tech
niques using known atmospheres. As an example of an application, perce
ntage recovery of compounds in a complex atmosphere was studied on Ten
ax GC and Carbotrap B.