Using Isotope Dilution Mass Spectrometry to Determine Aqueous Trichloroacetic Acid

Abstract
The development, verification, and application of a method based on isotope dilution gas chromatography‐mass spectrometry to determine aqueous trichloroacetic acid (TCAA) at the micrograms‐per‐litre level are described. The simultaneous determination of aqueous chloroform is also demonstrated. Trichloroacetic acid is shown to be a significant by‐product of the chlorination of raw waters in the laboratory and to constitute a large fraction of the total organic halide (TOX) formed. Analysis of finished‐water samples indicated that TCAA, like trihalomethanes, is ubiquitous. Positive correlations exist between the levels of TCAA in laboratory‐chlorinated raw waters and in finished waters and measured TOX.