OBJECTIVETo establish a method for determination of chloropicrin in the air of workplace by gas chromatography with liquid absorption collection.

METHODSChloropicrin in sample air was collected by absolute ethyl alcohol in a porous glass plate absorption tube. Following direct sample loading, samples were separated by gas chromatography and detected with a micro-electron capture detector. The present method was compared with the national standard method.

RESULTSThe range of linearity was 0-3.0 µg/ml, and the regression equation was y = 3488.80x-57.84, with a correlation coefficient of 0.999 4. The detection limit was 0.003 µg/ml, with a minimum detectable concentration of 0.005 mg/m³ based on a 3.0 L sampling volume. The average recovery rate was 98.9%∼103.2%. The within-run precision was 0.96%-2.12%, and the between-run precision was 2.75%-4.59%. The sampling efficiency was 98.6%. Samples in porous glass plate absorption tube could be stored at 4 °C for at least 5 days. The result ratio of this method to the national standard method was 97.7%-108.0% .

CONCLUSIONThe present method meets the requirements of "Guide for establishing occupational health standards-Part 4: Determination methods of air chemicals in workplace" (GBZ/T 210.4-2008), and is feasible for determination of chloropicrin in the air of workplace.