GC Analysis of Trihalomethanes in Drinking Water — A Rapid and Direct Quantitative Method

association of waterborne chloroform in drinking water with low birth weight, prematurity, and intrauterine growth retardation (2). Animal studies have found possible relationships between oral exposure to various trihalomethanes and fetotoxicity and sperm abnormalities (3,4). The U.S. Environmental Protection Agency (EPA) has published the Stage 1 Disinfectants–Disinfection By-products Rule to regulate total trihalomethanes at a maximum allowable annual average level of 80 ppb. In December 2001, this standard replaced the 100-ppb maximum allowable annual average level for large surface water public water systems. The standard will become effective for small surface water and all ground water systems in December 2003 (http://www.epa.gov/enviro/html/icr/gloss_ dbp.html#tthm). Additionally, some bottled water producers in California and Florida have adopted a 10g/L total trihalomethane limit, which is a standard recommended by the International Bottled Water Association (IBWA) (see “Bottled Water, Pure Drink or Pure Hype?” Natural Resources Defense Council, http://www. nrdc.org). Different analytical methods have been developed to analyze trihalomethanes in drinking water. The most widely used are based on gas chromatography (GC) with electron-capture or mass spectrometry detecThe determination of disinfection by-products such as trihalomethanes has become extremely important because of the current regulatory testing requirements of the U.S. Environmental Protection Agency. The difficulties and expenses involved in regulatory testing require a low-cost, simple, quantitative test for these compounds. The authors developed a gas chromatography method using electron-capture detection for measuring trihalomethanes in drinking water without solvent extraction or concentration steps. The assay allowed the determination of chloroform, dichlorobromomethane, chlorodibromomethane, and bromoform. GC Analysis of Trihalomethanes in Drinking Water — A Rapid and Direct Quantitative Method