A complete method for sampling and analyzing of energetic compounds in the atmosphere is described. The method consists of the hyphenation of several techniques: active air sampling using a solid-phase extraction cartridge to collect the analytes, extraction of the sorbed analytes by toluene/methyl tert-butyl ether modified supercritical fluid extraction (SFE), and analysis of the extract by large-volume injection GC-nitrogen/phosphorus detection. The GC system is equipped with a loop-type injection interface with an early solvent vapor exit, a utilizing concurrent solvent evaporation technique. Chemometric approaches, based on a Plackett-Burman screening design and a central composite design for response surface modeling, were used to determine the optimum SFE conditions. The relative standard deviations of the optimized method were determined to be 4.3 to 7.7%, giving raise to method detection limits ranging from 0.06 to 0.36 ng in the sampling cartridge, equivalent to 6.2-36.4 pg/L in the atmosphere, standard sampling volume 10 L. The analytical method was applied to characterize headspace composition above military grade trinitrotoluene (TNT). Results confirm that 2,4-dinitrotoluene (DNT) and 1,3-dinitrobenzene (DNB) constitute the largest vapor flux, but TNT, 2,6-DNT, and trinitrobenzene TNB were also consistently detected in all the samples.
Quantitation of a variety of tetra-, penta-, and hexacyclic
aromatic sulfur heterocycles (thiaarenes) in workplace air of
an an aluminum reduction plant has been made by help
of gas chromatography with atomic emission detection (GC-AED). Personal exposure to those thiaarenes and to
polycyclic aromatic hydrocarbons depending on work
categories has been evaluated. Summarized concentrations
of the thiaarenes investigated have been found to be 0.4−19.0 μg/m3. When using sulfur selective AED, samples
could be analyzed without a prior separation of the thiaarenes
from the PAH. The present data indicate a contribution
of thiaarenes to the overall toxicity of coal tar pitch volatiles
in this work environment.
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