Determination of o-toluidine in workplace air by solvent desorption-gas chromatography

Abstract

To establish solvent desorption gas chromatograph method for o-toluidine determination in workplace air. The o-toluidine vapour in workplace air was collected with silicone tube, and desorbed with absolute ethanol. Then the desorption solution was separated with polyethylene glycol HP-INNOWax capillary column(30 m×0. 32 mm, 0. 50 μm)and measured with flame ionization detector. Detection limit of the method was 0. 18 μg/mL, quantification limit of the method was 0. 60 μg/mL, quantitative determination range of method was 0. 60-245. 37 μg/mL, and the minimum quantitative determination concentration was 0. 20 mg/m~3(based on 3. 0 L sample). The method had a good reproducibility, the relative standard deviation was 1. 0%-3. 5%, the average of desorption efficiency was 98. 7%, and the average of sampling efficiency was 93. 7%. The penetrating capacity of 200 mg alkaline silicone was over than 2. 1 mg, and the samples at room temperature could be preserved for 15 days at least. Methanol, toluene, chlorobenzene, acetoacetic ester, aniline, N-methylaniline, N, N-dimethylaniline, o-nitroaniline, p-toluidine or m-toluidine coexisted in the air did not interfere during the determination of o-toluidine. The method with low determination concentration, high accuracy and precision, is feasible for determination of o-toluidine vapour in workplace air.