A novel vapor dynamic headspace enrichment device was set up for nontarget screening of volatile organic compounds (VOCs) in drinking water. The main operating parameters of this device, such as length of distillation tube, volume of collected condensate, and choice of absorbent, were optimized. In this device, vapor was utilized as a purge gas and water was utilized as a absorbent. With the help of the device, one liter of water sample could be concentrated to 5 mL and the sensitivity of traditional purge and trap-gas chromatography-mass spectrometry (P&T-GC-MS) could be improved 1 -2 orders of magnitude. Source and disinfected water samples from a water treatment plant were analyzed with this method. Compared with the traditional P&T-GC-MS analysis without pre-enrichment, the numbers of identified VOCs were improved from 0 to 16 for source water and 5 to 35 for disinfected water samples. It is also shown that there are many halide compounds in VOCs in disinfected water which do not exist in source water.%以饮用水中痕量挥发性有机物(VOCs)非目标筛查为目的,构建了一种新型的大体积水样高倍富集装置.对其精馏管长度、回收冷凝液体积、吸收介质等影响富集效果的关键因素进行了优化.该装置以水蒸气为吹扫气,同时以水作为吸收剂,将1L水样富集浓缩至5 mL后,可使原有吹扫捕集-气相色谱-质谱法(P&T-GC-MS)分析VOCs的灵敏度提高1～2个数量级.用该方法对某净水厂的源水与出厂水进行了痕量VOCs的定性分析与比较.与传统P&T-GC-MS方法相比,本方法对两种水样的污染物检出数目由原来的无检出和5种分别提高至16种和35种.分析结果表明饮用水消毒前后污染物的种类及含量存在显著差异.
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