GAS-CHROMATOGRAPHIC MASS-SPECTROMETRIC DETERMINATION OF HALOGENATED ACETIC-ACIDS IN WATER AFTER DIRECT DERIVATIZATION

A previously developed difluoroanilide derivatization method was used for the determination of trace levels of halogenated acetic acids (HAAs), including bromoacetic acids, in water. The derivatives formed by the reaction were separated with a gas chromatograph-mass spectrometer equipped with a fused-silica capillary column and detected by selected ion monitoring. Five acids (chloro- and bromoacetic acids) in water could be determined at mug l-1 levels. The recoveries for 10 mug l-1 of analyte in natural waters (lake and sea waters) were greater than 85%. However, under the conditions used, tribromoacetic acid could be determined only at higher concentration levels. The proposed method was successfully used to determine concentrations of HAAs in a range of natural waters. HAA formation from raw river water was investigated by laboratory chlorination experiments.