液液萃取气相色谱法测定饮用水中的25种消毒副产物

Determination of 25 disinfection by-products in drinking water using liquid-liquid extraction and gas chromatography

目的建立液液萃取气相色谱法测定饮用水中25种消毒副产物(7种卤乙醛、7种卤乙腈、7种卤代硝基甲烷及4种卤乙酰胺)。方法采用液液萃取气相色谱技术,对毛细管色谱柱型号、进样口温度、盐析试剂浓度、pH值等实验参数进行优化,建立检测方法并进行方法验证。结果采用HP-5 MS UI(30 m×0.25 mm,0.25μm)色谱柱,进样口温度180℃,氯化钠加入量8 g/50 mL水样,样品pH 4~5作为最终的实验条件。方法线性范围为0.20~15μg/L,线性相关系数r>0.999;方法检出限为0.008~0.088μg/L;纯水与管网水加标浓度1.0μg/L时的回收率分别为81%~106%和75%~117%,相对标准偏差均<4%,纯水与管网水加标浓度12μg/L时的回收率分别为92%~101%和86%~106%,相对标准偏差分别<4%及<2%。结论该方法简单、灵敏、高效,适合于同时测定饮用水中25种消毒副产物。

OBJECTIVE To establish a liquid-liquid extraction and gas chromatography method for the determination of 7 kinds of haloacetaldehydes,7 kinds of haloacetonitriles,7 kinds of halonitromethanes and 4 kinds of haloacetamides in drinking water.METHODS A liquid-liquid extraction gas chromatography technique was employed.Experimental parameters,such as capillary column type,inlet temperature,concentration of salting out reagent and sample pH were optimized to develop an analytical method,and then method validation was conducted.RESULTS HP-5 MS UI column(30 m×0.25 mm,0.25μm),inlet temperature at 180℃,addition of 8 g sodium chloride in 50 mL water sample and pH 4-5 were chosen as the final parameters.Good correlation coefficients were obtained in the linear range of 0.20-15μg/L,with r greater than 0.999.Methods detection limits were between 0.008-0.088μg/L.When spiked concentration was 1.0μg/L for pure water and tap water,the recoveries were 81%-106%and 75%-117%,respectively,and relative standard deviations were both less than 4%.When spiked concentration was 12μg/L for pure water and tap water,the recoveries were 92%-101%and 86%-106%,respectively,and relative standard deviations were less than 4%and 2%,respectively.CONCLUSION This method is simple,sensitive,and effective.It is suitable for simultaneous determination of 25 disinfection byproducts in drinking water.