Moving towards on-line, real-time monitoring of haloacetic acids at concentrations relevant to drinking water utilities

摘要

A fully-automated preconcentration procedure for haloacetic acids (HAAs) with on-line internal standardization using sequential injection analysis (SIA) is described. The SIA procedure is integrated as a module with post-column reaction ion chromatography (PCR-IC) for on-line, real-time analysis of HAAs in drinking water distribution systems. The method detection limits for the individual HAAs species were all less than 0.9 μg/L, an average improvement by a factor of 5.6 compared to previous PCR-IC analyzers. Side-by-side comparison studies of HAAs analysis in 14 real-world drinking water samples from Alabama, Arkansas, Kentucky, Minnesota, Missouri, Mississippi, New York, Pennsylvania and Tennessee are summarized that compare the SIA-PCR-IC to USEPA Method 552.3 with the bias values typically less than 5 μg/L for eight of the nine individual HAAs. The improved signal to noise ratio of the SIA-PCRIC allowed for evaluations of peristaltic pump tubing lifetime and the stability of the nicotinamide reagent.