中文摘要：

报告了自行研制的质子转移反应质谱（Proton Transfer Reaction Mass Spectrometry，P1R—MS）装置结合动态气体提取技术直接测量水中苯浓度的新方法。N2连续地将水溶液中的苯提取出来，用质子转移反应质谱测量其在液面顶空中的分压强P随时间的变化关系，从而得到苯的亨利常数H利用亨利定律就可以给出苯在水溶液中的浓度。考察了苯在提取气体及水溶液中达到平衡需要的液面高度，测量了28℃时苯的亨利常数。以此为基础测试了水中苯的浓度．测量结果与配制的溶液浓度相一致。PIR—MS结合动态气体提取技术测量水中苯的浓度，检出限为1μg／L。方法可以拓展到水中其它挥发性有机物浓度的测量。

英文摘要：

A new method for determination of benzene in water is presented by using a dynamic approach combined with the stripping cell directly to a proton transfer reaction mass spectrometer （PTR-MS）. A flow of pure N2 bubbling through a solution continuously stripped benzene in water and the partial pressure of benzene in headspace of water was measured by PTR-MS. The Henry＇s law constant （HLC） was investigated through recording the partial pressure of benzene dependence on time. The concentration of benzene in water was obtained by the HLC and the partial pressure of benzene in headspaee of water through Henry＇s Law. Experiments tested the equilibrium of benzene components between gas-bubbles and water as a function of liquid depth; The HLC of benzene was measured at 28 ℃. The validation of this method was demonstrated by measuring the known concentration of benzene in water. Our PTR-MS coupling the stripping cell has the limits of detection as low as 1 μg/L for benzene in water. The method described has fast response, low limit of detection and high sensitivity, and can be extended to other VOCs analysis in water.