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Haloacetic acids (HAAs) are among disinfection byproducts that are producedduring chlorination of water containing natural organic matter and bromide. FiveHAAs are currently regulated in finished drinking water by the U.S. Environmental Protection Agency (USEPA). Themethods that are approved for compliance monitoring include USEPA Method 552.1,552.2, 552.3 and Standard Method 6251B. These methods are fairly challengingand time consuming as each requires an extraction and derivatization procedure,which is followed by gas chromatography (GC) with electron capture detection(ECD) using a procedural calibration technique. Ion chromatography-massspectrometry (IC-MS/MS) offers a sensitive and selective alternative that doesnot require sample pretreatment or procedural calibration. Water samples aredirectly injected into an ion chromatograph coupled to a triple quadrupole massspectrometer. This method is currently being evaluated by the USEPA at the Office ofGround Water and Drinking Water's laboratory in Cincinnati, Ohio as Method 557.Water samples from three separate sources were used to compare HAAamounts using USEPA 552 and the new method under validation, USEPA 557.Excellent peak resolution and linearity are achieved for analyte concentrationsthat range between 0.4 g/L and 100 g/L in a matrix containing up to 250 mg/Leach of chloride and sulfate, and 30 mg/L of nitrate. Using sup13/supCClHsub2/subCOOH as aninternal standard, the detection limit is less than 0.4 g/L for each of the fiveregulated HAAs and less than 1 g/L for the other four. No significant matrixeffects are observed in the synthetic matrix, and recoveries of all nine HAAs aregreater than 90% for both methods. Using spike recoveries of all nine HAA's,variability between methods was between 70 and 130% for most determinations. Includes tables, figures.

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Edition: Vol. - No. Published: 11/01/2009 Number of Pages: 40File Size: 1 file , 1.9 MB