[Determination of volatile organic compounds in air by portable gas chromatography-mass spectroscopy]

Objective: To investigate the method of portable gas chromatography-mass spectroscopy (GC-MS) for the determination of common volatile organic compounds in air. Methods: The static volumetric method was used, with highly purified nitrogen gas as the diluents gas, to prepare the mixed standard gas of common volatile organic compounds with various mass concentrations. A portable GC-MS handheld probe was used for sampling and measurement, retention time and characteristic ion were used for qualitative analysis, and the full-scan mode was used for quantitative analysis. Results: The correlation coefficient of 12 volatile organic compounds determined by this method was higher than 0.999. The minimum detection mass concentration was 0.02~0.12 mg/m³, and the minimum quantitative mass concentration was 0.07~0.40 mg/m³. The relative standard deviation of precision was 4.10%~12.50%; the relative deviation of acetone, benzene, methylbenzene, and dimethylbenzene was-13.56% , 9.03% , -10.82% , and 8.67% , respectively. Conclusion: Portable GC-MS method can be used for the qualitative analysis and quantification of volatile organic compounds in occupational hazard factors and provide technical supports for identification of occupational hazard factors.