苏玛罐采样-多重毛细柱捕集-气相色谱-质谱法测定空气中挥发性有机硫化合物

Determination of volatile organic sulfur compounds in air by summa canisters sampling–multiple capillary column trapping–GC–MS

建立了苏玛罐采样-多重毛细柱捕集-气相色谱-质谱法测定环境空气中二硫化碳、甲硫醇、甲硫醚、二甲二硫醚。采用DB-1色谱柱,进样体积为10~350 mL,程序升流进样,考察了样品保存时间、湿度对捕集系统的影响。结果表明,4种化合物在1.0~20.0μmol/mol范围内线性良好,相关系数均大于0.998,检出限为0.15~0.24μg/m~3,满足GB 14454-1993恶臭污染物厂界一级标准限值分析要求,同时低于人的嗅觉阈值。样品加标回收率为94%~104%,测定结果的相对标准偏差为1.5%~4.8%(n=6)。该方法样品前处理不需使用液氮制冷,简单快速,准确度高,重复性好,检出限低,适合实验室和在线环境空气有机硫化合物的分析。

A method was established for the determination of carbon disulfide,methyl mercaptan,methyl sulfide and dimethyl disulfide in ambient air by summa canisters sampling–multiple capillary column trapping–GC–MS.DB–1 column was used,the injection volume was 10–350 mL,and the samples were injected by program flow.The effects of sample storage time and humidity on the capture system were investigated.The results showed that the linearity of the four organic sulfur compounds was good in the range of 1.0–20.0μmol/mol with the correlation coefficients more than 0.998,and the detection limits were 0.15–0.24μg/m3,which met the requirements of GB 14454–1993 grade I standard for odor pollutants at the factory boundary,which were lower than human olfactory threshold.The recoveries of standard addition were 94%–104%,and the relative standard deviations of determination results were 1.5%–4.8%(n=6).The method is simple,rapid,accurate,reproducible and low detection limit without liquid nitrogen refrigeration.It is suitable for the analysis of sulfide in laboratory and on-line ambient air.