Headspace solid phase microextraction-gas chromatography for the determination of trihalomethanes in fish

Abstract

The aim of this work is to develop a method for determining trihalomethanes (THMs) in fish samples. The proposed method uses solid phase microextraction and gas chromatography with an electron capture detector. Factors such as temperature, extraction time and type of fiber were assessed to maximize the performance of the extraction technique. The performance of the method was evaluated using selectivity, linearity, precision, accuracy and limits of detection (LOD) and quantification (LOQ). The new method allows analysis of THMs with appropriate selectivity and linearity, with coefficient of correlation > 0.98. The LOD and LOQ of the analytes of interest are from 0.11 to 0.35 μg kg− 1 and 0.35 to 1.18 μg kg− 1, respectively. In addition, the relative standard deviation (RSD) was between 1.6 and 8%, and the relative recovery was between 76 and 113%. The optimized and validated method was applied to fish samples purchased from the Viçosa (MG) local market. At least three of the THMs of interest were detected in most of the analyzed fish samples with maximum values for the concentration of chloroform, bromodichloromethane and bromoform at 8.33, 0.42 and 2.41 μg kg− 1, respectively.