Simultaneous Determination of 10 Alcohol and Ether Compounds in Air of Workplace by Gas Chromatography-Mass Spectrometry after Thermal Desorption

By comparing the adsorption ability of stainless steel adsorption tubes filled with different adsorbents for 10 alcohol and ether compounds, optimizing the conditions of thermal desorption, investigating the effects of different chromatographic columns and the storage time of sample on the results of determination, a method for the simultaneous determination of 10 alcohol and ether compounds in air of workplace by gas chromatography-mass spectrometry after thermal desorption was proposed. The adsorption tube filled with Tenax GR was used to collect gas sample. After collection, both ends of the adsorption tube were sealed, and the thermal desorption was carried out under the following conditions:the first thermal desorption temperature of 220℃, the second thermal desorption temperature of 240℃, the purge time of 4 min, and the sample injection time of 50 s. The desorbed gas was entered into gas chromatograph, and the target compounds were separated on DB-624 capillary column and detected by mass spectrometer with electron impact ion source in selected ion monitoring mode. It was shown that linearity relationships between masses of 10 alcohol and ether compounds and their peak areas were kept in the range of 10-300 ng, with detection limits (3.143s) in the range of 0.5-1.9 ng. Test for recovery was made on the blank sample by standard addition method, giving results in the range of 70.5%-125%, and RSDs (n=6) of the determined values were ranged from 1.0% to 20%. This method was applied to analysis of the actual sample, n-butyl alcohol, isobutyl alcohol and sec-butyl alcohol were detected, with detection amounts of 0.013, 0.007, 0.008 mg·m^-3.