饮用水中8种挥发性卤代烃的顶空热脱附-气相质谱联用检测法

Determination of eight volatile halogenated hydrocarbons in drinking water by headspace thermal desorption-gas mass spectrometry

【目的】建立顶空串联热脱附-气相质谱联合测定饮用水中氯乙烯、三氯乙烯、四氯乙烯、四氯化碳、三氯甲烷、二氯一溴甲烷、一氯二溴甲烷、三溴甲烷8种挥发性卤代烃的方法。【方法】水样于顶空瓶中60℃保持40 min,经顶空将挥发性物质转移至冷阱,再经热脱附导入气相质谱仪测定。【结果】8种物质的线性范围分别为氯乙烯0.2~20.0µg·L^(−1),三氯甲烷0.1~20.0µg·L^(−1),四氯化碳0.02~20.00µg·L^(−1),三氯乙烯0.2~20.0µg·L^(−1),二氯一溴甲烷0.3~20.0µg·L^(−1),四氯乙烯0.1~20.0µg·L^(−1),一氯二溴甲烷0.4~20.0µg·L^(−1),三溴甲烷1.0~20.0µg·L^(−1),线性相关系数均为r>0.997。定量限分别为0.162、0.073、0.016、0.184、0.270、0.071、0.356、0.813µg·L^(−1),加标回收率分别为98.0%~100.7%、102.0%~110.0%、99.2%~101.2%、95.6%~96.4%、96.0%~102.2%、100.0%~102.0%、98.9%~105.0%、94.0%~102.8%。【结论】该方法操作简便,灵敏快速、准确可靠,适用于饮用水中痕量氯乙烯等8种挥发性卤代烃的定性定量分析。

[Objective]To establish a method for the determination of 8 volatile halogenated hydrocarbons in drinking water,including vinyl chloride,trichloroethylene,tetrachloroethylene,tetrachloromethane,chloroform,dichlorobromomethane,dichlorodibromomethane,and tribromomethane by headspace thermal desorption-gas mass spectrometry.[Methods]The water sample was kept in the headspace bottle at 60℃for 40 min,and the volatile matter was transferred to the cold trap,subjected to thermal desorption,then analyzed by gas chromatographymass spectrometry.[Results]The linear ranges were 0.2‒20.0µg·L^(−1) for vinyl chloride,0.1‒20.0µg·L^(−1) for chloroform,0.02‒20.00µg·L^(−1) for tetrachloromethane,0.2‒20.0µg·L^(−1) for trichloroethylene,0.3‒20.0µg·L^(−1) for dichlorobromomethane,0.1‒20.0µg·L^(−1) for tetrachloroethylene,0.4‒20.0µg·L^(−1) for dichlorodibromomethane,and 1.0‒20.0µg·L^(−1) for tribromomethane.All the correlation coefficients were more than 0.997.The respective quantitative limits were 0.162,0.073,0.016,0.184,0.270,0.071,0.356 and 0.813µg·L^(−1),and the respective recoveries were 98.0%‒101.0%,102.0%‒110.0%,99.2%‒101.0%,95.5%‒96.2%,96.0%‒102.0%,100.0%‒102.0%,99.0%‒105.0%,and 94.0%‒103.0%.[Conclusion]The method is simple,sensitive,rapid,accurate and reliable,so it is applicable for the determination of 8 kinds of volatile halogenated hydrocarbons in drinking water.