Determination of trihalomethanes and some chlorinated solvents in drinking water by headspace technique with capillary column gas-chromatography

A simple and rapid headspace method for gas chromatographic determination of trihalomethanes and some chlorinated solvents in drinking water is described. The quantification is based upon the internal standard 1,1,2-trichloroethane, which elutes in the middle of the chromatogram. The relative standard deviations for most of the substances are between 0.8–8% for concentrations of 1 and 50 μg/l, respectively. The limits of quantification (LOQ) are ≤0.1 μg/l for three of the THM analytes and 0.2 μg/l for bromoform. The chlorinated solvents have LOQ≤0.1 μg/l except dichloromethane which has 2 μg/l. The analytes show linear ranges up to 75 μg/l. The results of THM from the survey of 209 Swedish drinking water samples showed that 3% exceeded the Swedish limit value of 50 μg/l of total THM.