Working out a procedure for determining potentially hazardous volatile organic compounds (trichloroethylene and tetrachloroethylene) in ambient air

He article dwells on results obtained via experimental research on working out a gas chromatography procedure for determining trichloroethylene and tetrachloroethylene in ambient air. Experiments were performed on substances which had low limits of detection with gas-liquid chromatography with electron capture detection (GLC/ECD) when examined substances were absorbed from ambient air on Tenax TA sorbent. Optimal gas chromatography parameters were established with a hardware-software complex based on «Crystal-5000» gas chromatographer and use of a column from IDBPX-VOL series, 60 m·0.32 mm·1.8 µm, under the following temperatures: column, 50-230 оС; evaporator, 250 оС; detector, 250 оС. The developed capillary gas chromatography procedure allows determining trichloroethylene in concentrations ranging from 0.000146 to 0.00146 mg/m3, and tetrachloroethylene, from 0.000081 to 0.00081 mg/m3 with inaccuracy not exceeding 25.0 %. We performed metrological assessment of the procedure and it allowed determining quality of analysis results for trichloroethylene and tetrachloroethylene; they were as follows: precision, 21.97 % and 14.3 %: repeatability, 4.22 % and 3.38 %; reproducibility, 5.66 % and 4.9 %. Limit of detection (LOD) for trichloroethylene and tetrachloroethylene was Сmin = 0.0000038 mg/dm3 and Сmin = 0.00000083 mg/dm3 accordingly. Limit of quantitative determination (LOQ) was Сlim = 0.000013 mg/m3 for trichloroethylene, and Сlim = 0.0000028 mg/m3 for tetrachloroethylene. The developed procedure allowed detecting contents of the examined substances in ambient air near a construction site and a dry-cleaner’s, trichloroethylene in a range from 0.00001 mg/m3 to 0.0009 mg/m3, tetrachloroethylene, from 0.000011 mg/m3 to 0.00039 mg/m3. This unified high-sensitive and selective procedure is recommended for systemic control over potentially hazardous volatile organic compounds in ambient air as it allows providing objective and reliable hygienic assessment of chemical safety and quality of the environment and health risk assessment.