质子转移反应质谱动态测量苯系物的亨利常数

采用动态气体提取方法, 使用自行研制的质子转移反应质谱(PTR-MS)装置, 研究了挥发性苯系物亨利常数的测量方法. 考察了苯在提取气体与水溶液中达到平衡需要的液面高度, 通过25 ℃条件下苯的亨利常数测量验证了动态气体提取方法结合质子转移反应质谱测量亨利常数的有效性, 报告了11种苯系物的亨利常数测量结果. 与常规的亨利常数测量方法相比, 本方法具有简单、快速、人为干扰少等优点.

Dynamic Measurements of Henry's Law Constant of Aromatic Compounds Using Proton Transfer Reaction Mass Spectrometry

Henry’s lawconstants (HLC) of volatile aromatic compounds were determined using a dynamics approach by coupling a stripping cell directly to a homemade proton transfer reaction mass spectrometry (PTR-MS). The intensity of C6H6H+ ion dependence on liquid height of benzene solution was explored in order to ensure the equilibrium of aromatic compound components between the gas-bubbles and water. The HLC of benzene measured at 25 ℃ is in agreement with the reported value in literature, showing that this method is valid. HLC values were presented for benzene, toluene, ethylbenzene, chlorobenzene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,4-dichlorobenzene, 1,2-dimethylbenzene, 1,3-dimethylbenzene, 1,4-dimethylbenzene, and 1,2,4-trimethylbenzene. Compared to the conventional techniques, the dynamics extraction combination with PTR-MS is simple, fast, and less prone to artifacts in the HLC measurement.