Yuefeng Xie, Postdoctoral Research Associate

Denise C. Springborg, Research AssistantDavid A. Reckhow, Associate Professor

A liquid-liquid solvent microextraction-acidic methanol methylation method was developed for the analyses of haloacetic acids and ketoacids in drinking water by gas chromatography-electron capture detector. The method detection limits were determined to be 0.2 µg/L for dichloroacetic acid, 0.09 µg/L for trichloroacetic acid, 0.4 µg/L for monobromoacetic acid and 0.07 µg/L for dibromoacetic acid. The spike recoveries were 115% for monochloroacetic acid, 111% for dichloroacetic acid, 109% for trichloroacetic acid, 118% for monobromoacetic acid and 108% for dibromoacetic acid. Comparing these method detection limits and recoveries with those reported in the Standard Method showed both methods to be comparable except that for monochloroacetic acid. The statistical study indicates that there is no difference between the HAA concentration with diazomethane methylation and that with acidic methanol methylation. For glyoxylic acid and pyruvic acid analyses, both diazomethane and acidic methanol methylation gave comparable results. More study is needed to improve the methylation efficiency of monochlroacetic acid and ketomalonic acid.