Detection of 2,4,6-trichloroanisole in chlorinated water at nanogram per litre levels by SPME-GC-ECD

摘要

A method involving solid-phase micro extraction ( SPME) and gas chromatography with electron capture detection (SPME-GC-ECD) has been optimised for identification and quantification of 2,4,6-trichloroanisole (TCA) at ng L-1 concentrations in disinfected ( chlorinated) water samples. A central composite design was used for factorial analysis of four factors, three factors related to the SPME (PDMS fibre) procedure ( adsorption time, temperature of the sample during headspace sampling, and desorption time) and one related to the GC operation ( the rate of increase of the temperature of the GC oven). Good linearity ( linear correlation coefficient greater than 0.999) was observed for TCA concentrations up to 50 ng L-1, limits of detection and quanti. cation of 0.7 and 2.3 ng L-1, respectively, and good precision ( relative standard deviation 2.8 and 3.4 for 5 and 30 ng L-1 of TCA, respectively). Besides TCA, this system also enables the detection and quanti. cation of the four trihalomethanes in the mu g L-1 concentration range with limits of detection and quanti. cation of approximately 0.3 mu g L-1 and 1 mu g L-1, respectively.