饮用水中11种挥发性有机物的顶空-气相色谱测定法

Determination of 11 kinds of volatile organic compounds in drinking water by headspace gas chromatography

目的建立饮用水中二氯甲烷、苯、甲苯、1,2-二氯乙烷等11种挥发性有机物的顶空-气相色谱法。方法 10 ml样品添加0.30 g NaCl后,在65℃平衡30 min,经顶空进样后,采用Hp-Wax毛细管色谱柱进行分离,以氢火焰离子化检测器进行检测,以保留时间定性,外标法定量。结果二氯甲烷、苯、甲苯、1,2二氯乙烷、乙苯、对二甲苯、间二甲苯、异丙苯、邻二甲苯、氯苯、苯乙烯的线性范围分别为17.4～324、5.5～97、4.1～80、24.5～288、3.6～99、7.2～80、6.2～81、4.1～94、4.2～80、6.4～103和6.2～97μg/L,最低检出浓度为1.1～7.4μg/L,加标回收率为85.8%～107.0%,相对标准偏差(RSD)为1.3%～5.6%(n=6)。结论该分析方法操作简单,基体干扰少,分析效率高,可对饮用水中11种挥发性有机物进行同时监测,便于在各基层单位开展相关的水质监测。

[Objective]To establish a method for determination of 11 kinds of volatile organic compounds（VOCs） such as methylene chloride,benzene,toluene,1,2-dichloroethane in drinking water by headspace gas chromatography.[Methods]Sample solution with 0.30 g/ml NaCl was equilibrated at 65 ℃ for 30 min,the VOCs were separated by HP-Wax capillary column,then detected by hydrogen flame ionization detector（FID） and quantified by external standard method.[Results] The linear range of dichloromethane,benzene,toluene,1,2-dichloroethane,ethylbenzene,p-xylene,m-xylene,cumene,o-xylene,chlorobenzene,styrene were 17.4-324,5.5-97,4.1-80,24.5-288.00,3.6-99,7.2-80,6.2-81,4.1-94,4.2-80,6.4-103,6.2-97 μg/L,respectively.The limit detection range were 1.1-7.4 μg/L（S/N=3）.The recoveries were 85.8%-107.0% and the relative standard deviations（RSDs） were 1.3%-5.6%（n=6）.[Conclusion]This method is simple,with less matrix interference and high efficiency,suitable for the simultaneous determination of 11 kinds of VOCs in drinking water,and convenient for water quality monitoring at the grassroots units.