A sensitive and specific solid-phase extraction–gas chromatography–tandem mass spectrometry method for the determination of 11 haloacetic acids in aqueous samples

A method for the analysis of 11 haloacetic acids in water samples has been developed. It involves enrichment of the target analytes from water samples by solid-phase extraction, derivatization to methyl esters, and gas chromatography coupled with tandem mass spectrometry determination. Gas chromatography conditions were optimized for a good separation of all haloacetic acids in a short runtime. Data were acquired in the multiple reaction monitoring mode. Six solid-phase extraction sorbents among the most widely used in environmental analysis were tested. Bakerbond SDB was retained because it has been shown to provide the best results for a large class of targeted haloacetic acids. The performances of the developed method have been assessed according to the French Standard NF T 90-210. The calibration curves for all the studied haloacetic acids had consistent slopes with r² values > 0.99. Quantification limits between 0.01 and 0.50 µg l⁻¹ were achieved. Satisfactory repeatability (relative standard deviation ≤ 14.3%) and intermediate precision (relative standard deviation ≤ 15.7%) were obtained. Applied to the analysis of 15 untreated water samples collected from three rivers, the method allowed the detection of five haloacetic acids including monochloroacetic acid (in 100% of the samples, <0.5–1.85 µg l⁻¹), dichloroacetic acid (87%, <0.05–0.22 µg l⁻¹), trichloroacetic acid (93%, <0.05–0.52 µg l⁻¹), dibromoacetic acid (53%, <0.01–0.40 µg l⁻¹), tribromoacetic acid (20%, <0.05–0.14 µg l⁻¹), and bromodichloroacetic acid (6%, < 0.05 µg l⁻¹).