饮用水中三卤甲烷的顶空-气相色谱-质谱联用检测方法及健康风险评估

摘要

A selective ion monitoring (SIM) method was established to detect the concentration of trihalomethanes (THMs) in drinking water in N city by HS-GC-MS. And the headspace conditions was optimized to improve the sensitivity and efficiency of detection. It was applied to the test of THMs in the 4 districts of N city in June, July and August of 2016;th e carcinogenic risk of THMs through the oral route of exposure was calculated according to the EPA-recommended health risk assessment model. The results show the optimized method is effective and efficient in the determination of THMs in drinking water in the range of 2-100 μg/L. The value that calculated by content of THMs in drinking water reaches to 10-4 to 10-6, indicating a carcinogenic risk, but is still at an acceptable level of risk. The major risk factor is CHCl2Br. This study presents a further understanding of health risks of disinfection by-products (DBPs) in drinking water in N city, which will also provide reference for safety evaluation of drinking water in the future.%利用顶空-气相色谱-质谱联用仪建立了选择离子扫描方法 (SIM) 用以检测饮用水中三卤甲烷含量, 并针对顶空条件进行优化以提高检测的灵敏度及效率.将该方法应用于N市4个小区2016年6—8月饮用水中三卤甲烷含量的检测;同时基于美国环境保护署 (EPA) 推荐的健康风险评价模型对经口暴露途径的三卤甲烷的致癌风险进行评估.研究结果表明, 该方法在2～100μg/L范围内可以准确高效地检测饮用水中的三卤甲烷.对三卤甲烷含量的致癌风险评估发现, N市饮用水中三卤甲烷的致癌风险计算值为2.74×10-5, 在10-4～10-6之间, 提示存在致癌风险, 但在可接受的风险水平, 其中CHCl2Br对总致癌风险贡献最大.该研究对N市饮用水中消毒副产物的健康风险有了进一步了解, 可为今后开展饮用水安全评价提供参考.