Brown Michael A, Miller Sarah, Emmert Gary L
The University of Memphis, Department of Chemistry, Memphis, TN 38152, USA.
Anal Chim Acta. 2007 Jun 5;592(2):154-61. doi: 10.1016/j.aca.2007.04.020. Epub 2007 Apr 20.
A method using an automated on-line purge and trap gas chromatograph with a dry electrolytic conductivity detector (DELCD) has been developed for monitoring four regulated trihalomethanes in drinking water distribution systems. This analyzer samples trihalomethanes from drinking water by pervaporation through a silicone capillary membrane contained within a gas extraction cell (GEC) followed by preconcentration using an adsorbent trap. Trihalomethanes are subsequently desorbed from the trap onto a capillary column, separated and detected. The analyzer operates in real-time, samples directly from the drinking water distribution system and is fully automated. The optimization, operation, and evaluation of the analyzer and method are discussed. Method detection limits (MDL) are less than 1.0 microg L(-1) with acceptable estimates for accuracy, and precision. The results from two on-line monitoring studies in chlorinated and chloraminated distribution systems are presented. The performance of the method is compared directly to United Stated Environmental Protection Agency Method 502.2 and shows a very slight, but acceptable bias.
已开发出一种使用带有干式电解电导检测器（DELCD）的自动在线吹扫捕集气相色谱仪的方法，用于监测饮用水分配系统中的四种受控三卤甲烷。该分析仪通过渗透蒸发从饮用水中采集三卤甲烷，渗透蒸发通过气体萃取池（GEC）内的硅胶毛细管膜进行，随后使用吸附阱进行预浓缩。三卤甲烷随后从阱中解吸到毛细管柱上，进行分离和检测。该分析仪实时运行，直接从饮用水分配系统中采样，并且是完全自动化的。讨论了分析仪和方法的优化、操作及评估。方法检测限（MDL）小于1.0 μg L⁻¹，准确度和精密度估计值可接受。给出了在氯化和氯胺化分配系统中两项在线监测研究的结果。该方法的性能与美国环境保护局方法502.2直接进行了比较，显示出非常轻微但可接受的偏差。
