摘要目的 建立同位素稀释-气相色谱质谱联用方法测定生活饮用水中环氧氯丙烷.方法 在生活饮用水样品中加入D5-环氧氯丙烷内标应用液,先用活性炭对环氧氯丙烷进行富集,活性炭经2739×g离心脱水10 min,最后加入1.0 ml丙酮浸泡1h并进行解吸,解吸液用气相色谱-质谱法进行测定,同位素内标法定量,并对方法的检测限精密度和准确度进行评价,用该方法对某市25批次饮用水中环氧氯丙烷进行测定.结果 采用该方法测定环氧氯丙烷,在0.0645～3.8700 μg/L范围内线性良好,线性方程为Y=2.828X +4.91×10-2(r＞0.999),测定浓度为0.0806、0.3230、3.2300 μg/L时,环氧氯丙烷的RSD分别为7.9％、4.7％、3.1％；加标平均回收率在95.7％ ～98.7％之间,方法检测限为0.015 μg/L,定量限为0.052 μg/L.检测的25批饮用水中环氧氯丙烷含量均在检测限以下.结论 该方法较国家标准方法操作简单,且灵敏度高,准确性、重现性好,适应于生活饮用水中痕量环氧氯丙烷的测定.

abstractsObjective To establish a method for determination of the epichlorohydrin in drinking water by isotope dilution gas chromatography-nass spectrometry(GC-MS).Methods The internal standard solution D5-epichlorohydrin was added in drinking water sample.The epichlorohydrin was firstly collected by active carbon,and the adsorbent was then centrifuged at 2739 × g for 10 min to remove water.Finally,the epichlorohydrin was desorbed by dipping the active carbon in 1.0 ml acetone for 1 h.The desorbed solution was tested by GC-MS and quantified with isotopic internal standards.The detection limit,precision and accuracy of the assay were evaluated.This method was adopted to detect the epichlorohydrin in drinking water for 25 batches in a city.Results The determination method of epichlorohydrin represented a good linear relationship in the range of 0.0645-3.8700 μg/L,the linear regression equation was Y =2.828X + 4.91 ×10-2 (r ＞ 0.999).When the epichlorohydrin concentration were 0.0806,0.3230 and 3.2300 μg/L,the relative standard deviations (RSD) were 7.9％,4.7％ and 3.1％,respectively.The average recoveries were from 95.7％ to 98.7％.The limit of detection (LOD) was 0.015 μg/L,limit of quantification (LOQ) was 0.052 μg/L.The content of epichlorohydrin in the 25 cases of drinking water was under the limit of detection.Conclusion The method is more simple than the national standard method,with high sensitivity,accuracy and good reproducibility,which is suitable for detection of the trace amounts of epichlorohydrin in drinking water.