[Determination of volatile organic compounds in workplace by portable gas-chromatography]

To establish a portable gas chromatography (GC) method for the on-site rapid determination of epoxyethane, furan, dichloromethane, benzene, toluene in workplace.

By using dynamic dilutor, the volatile organic compounds (VOCs) standard gas was prepared and drawn to the capillary column of GC (PID) for separation and analysis. Based on the retention time and peak area, the VOCs was identified and quantified.

At the conditions of 60 degrees C column temperature and 9psi pre-pressure, The five VOCs were well separated. Good linear ranges were obtained within the ranges of 0.45 - 90.72 mg/m3 for epoxyethane, 0.22 - 44.50 mg/m3 for furan, 2.19 - 437.4 mg/m3 for dichloromethane, 0.32 - 13.29 mg/m3 for benzene, 0.38 - 15.68 mg/m3 for toluene, respectively. The correlation coefficient was not less than 0.999. The detection limits were 0.03, 0.04, 0.2, 0.008 and 0.03 mg/m3, respectively. The RSD were 0.79% - 2.4%, 1.5% - 1.9%, 0.97% - 1.8%, 2.3% - 3.2% and 3.4% - 4.6%, respectively. The average recovery were 101.4% - 108.4% 85.49% - 94.98%, 97.78% - 106.2%, 99.29% - 103.5% and 95.54% - 101.7% respectively. By using the 7890A GC method, the relative tolerance for the same gas samples were 0.091% - 8.8% for epoxyethane, 3.8% - 6.7% for furan, 0.77% - 9.4% for dichloromethane, 0.24% - 1.6% for benzene, 0.31% - 8.0% for toluene.

The method is portable, accurate, sensitive, rapid, and exhibits good separation and anti-interference ability. This method is suitable for the rapid detection of VOCs in workplace and also provides reference VOC detection method for the occupational health standard.