Method for the determination of chlorinated hydrocarbons in workplace air using gas chromatography

This analytical procedure is a validated measurement method for the determination of chlorinated hydrocarbons (CHCs) such as tetrachloroethylene, carbon tetrachloride, 1,1,1‐trichloroethane, 1,1,2‐trichloroethane, trichloroethylene, and trichloromethane and for monitoring their Occupational Exposure Limits (OELs) or MAK values in workplace air. Sampling is performed by drawing a defined volume of air through an adsorption tube filled with activated charcoal using a flow‐regulated pump. The flow rate is set to 50 mL/min with a recommended air sample volume of approx. 24 L at a sampling duration of 8 hours. The collected CHCs are desorbed with carbon disulphide containing n‐tetradecane as internal standard and analysed by means of gas chromatography fitted with flame ionisation detectors (FID) using two capillary columns of different polarity connected in parallel with the injector. The quantitative evaluation is based on calibration functions obtained by means of 6‐point calibrations with equidistant values in the lower working range. The limits of quantification (LOQs) are between 0.04 and 0.24 µg/m3 for the individual CHC with an expanded uncertainty between 15 and 17%. Joint Publication of the Analytical Subcommittee of the Chemistry Board of Experts of the Expert Committee Raw Materials and Chemical Industry of the German Social Accident Insurance and the Working Group “Air Monitoring Methods” of the Permanent Senate Commission of the DFG for the Investigation of Health Hazards of Chemical Compounds in the Work Area.