A simultaneous detection method for eight iodinated, brominated, and chlorinated haloacetic acid disinfection byproducts in human urine: liquid-liquid extraction-acidified methanol derivatization-gas chromatography.

Abstract

Haloacetic acids (HAAs) are among the most common drinking water disinfection byproducts (DBPs) and are of widespread concern due to their potential carcinogenicity and reproductive health risks. However, data on human exposure to HAAs are scarce. HAAs in urine have been identified as useful biomarkers for assessing exposure to DBPs via drinking chlorinated water. In this study, a suitable method for determining eight HAAs (including iodoacetic acid (IAA)) in human urine was developed and validated based on USEPA 552.3. HAAs were extracted from 5 mL of urine with methyl tert-butyl ether (MTBE), derivatized with acidified methanol and analyzed via gas chromatography with an electron capture detector (GC-ECD). Several optimization experiments were performed for the sample pretreatment step to establish a more sensitive and efficient analysis scheme. The method was tested in terms of linearity, accuracy, precision, and detection limits. The linear range of the method was 0.1-100 μg L^-1, with recovery rates from blank matrix-spiked samples ranging from 84.9% to 122.6%, relative standard deviations between 1.7% and 14.2%, detection limits from 0.013 to 0.3 μg L^-1, and quantitation limits from 0.043 to 1.0 μg L^-1. Finally, the method was applied to detect HAAs in actual human urine samples. Six HAAs were detected in 460 urine samples to varying degrees, with geometric mean concentrations ranging from 0.07 to 0.89 μg L^-1. The results demonstrate that the method is practical, and suitable for routine biomonitoring of HAAs in populations.