ANALYZING HAAS AND KETOACIDS WITHOUT DIAZOMETHANE

Currently available methods for analyzing haloacetic acids (HAAs) and ketoacids in water generally require the use of diazomethane for sampl e derivatization. This article proposes methods based on a less toxic, alternative methylating agent. The reagent in both cases is acidic me thanol. Side-by-side comparison of the proposed method for HAA analysi s and method 6251B showed no significant difference. These two methods were also found to give similar method detection limits and spike rec overies. The new O-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine (PFBHA) -acidic methanol derivatization analytical method for two ketoacids-gl yoxylic acid and pyruvic acid-was found to be comparable to the method using PFBHA-diazomethane. Additional study is needed to improve methy lation efficiency for ketomalonic acid. Work is also needed to further test the proposed HAA method with monochloroacetic acid and brominate d haloacetic acids.