Air sampling and gas-chromatographic determination of chlorodinitrobenzene isomers in the working environment

Chlorodinitrobenzene (CDNB) isomers are highly allergenic and irritating noxious substances used to produce explosives and dyes. A capillary gas-chromatographic method with flame-ionization detection has been developed for quantitative determination of 1-chloro-2,4-dinitrobenzene and 1-chloro-3,4-dinitrobenzene in workplace air. Polypropylene filters were used to separate CDNB aerosols from the air tested, and ethanol was used for extraction; recovery of the CDNB isomers was ca 94%. Use of a 60 m ´ 0.32 mm PE-1 capillary column at 180oC ensured appropriate sensitivity and precision of determination, and separation from other substances also present under industrial conditions. The detection limit achieved for injected samples was 0.02 žg of each CDNB isomer. This analytical procedure enables determination of CDNB isomers in workplace air at levels from 0.25 to 2.0 mg m-3.