吹扫捕集-气相色谱-质谱法同时测定水体中14种挥发性消毒副产物

Study on determination of 14 kinds of volatile disinfection by-products in water by purge and trap/gas chromatography/mass spectrometry

基于吹扫捕集-气相色谱-质谱联用法(P&T-GC-MS)技术建立了同时测定水中4类14种挥发性消毒副产物(V-DBPs)的方法,并对吹扫捕集条件及色谱条件进行了优化.水中的挥发性消毒副产物经吹扫捕集、热脱附,Rtx-624色谱柱分离,选择离子扫描模式方式进行测定,内标法定量.结果显示,校准曲线相关系数均大于0.999,方法检出限为1.72—374 ng·L^(−1),不同浓度下实际样品加标回收率为76.1%—114%,相对标准偏差为2.4%—13%.利用本方法对自来水开展检测,分别检出三氯甲烷、1,2-二氯乙烷、二氯一溴甲烷、氯乙腈、1,1-二氯丙酮、二氯乙腈、1,1,1-三氯丙酮等7种消毒副产物,检出浓度范围为3.21—16.6μg·L^(−1),检出率为36%—100%,其中二氯甲烷、三氯甲烷、1,2-二氯乙烷、二氯一溴甲烷、一氯二溴甲烷和三溴甲烷的结果均符合《生活饮用水卫生标准》(GB5749-2022)规定的限值要求.该方法具有前处理简单、重现性好、正确度高等特点,适用于同时快速测定水中14种挥发性消毒副产物.

A method for the simultaneous determination of 14 kinds of volatile disinfection byproducts(V-DBPs)in water was developed based on purge and trap gas chromatography-mass spectrometry(P&T-GC-MS),and the purge and trap conditions were optimized.The volatile disinfection by-products in water are separated by Rtx-624 chromatographic column after purging and trapping,thermal desorption,and determined by selecting ion scanning mode,and quantified by internal standard method.The results showed that the correlation coefficient of the calibration curve was greater than 0.999,the detection limit of the method was 1.72—374 ng·L^(−1).The recoveries of spiked samples at different concentrations were in the range of 76.1%—114%,and the relative standard deviation was 2.4%—13%.This method is used to detect disinfection by-products in tap water,Seven disinfection by-products including trichloromethane,1,2-dichloroethane,dichloromethane,chloroacetonitrile,1,1-dichloroacetone,dichloroacetonitrile and 1,1,1-trichloroacetone were detected respectively,and the detection concentration range is 3.21 ng·L^(−1)—16.6μg·L^(−1),detection rate is 36%—100%,the results of dichloromethane,chloroform,1,2-dichloroethane,dichloromonobromomethane,monochlorodibromodane,and tribromomethane all meet the limit requirements specified in the standards for drinking water quality(GB5749-2022).This method has characteristics of simple pretreatment,good reproducibility and high accuracy,and is suitable for the simultaneous rapid determination of 14 volatile disinfection by-products in water.