Optimization of a novel procedure for determination of VOCs in water and human urine samples based on SBSE coupled with TD-GC-HRMS.

In this study, stir-bar sorptive extraction and thermal desorption followed by gas chromatography coupled with high resolution mass spectrometry was applied for determination of halo-organic compounds (bromodichloromethane, dibromochloromethane, bromoform, and tetrachloroethylene) in water and human urine samples. Time of extraction and stirring speed were optimized. The results show that the optimum extraction time is 30 min with 600 rpm of stirring speed with Twister of 20 mm in length and 1.0-mm film thickness of PDMS (126 microL). The calibration curves, limits of detection and quantification for all compounds were calculated. This procedure is characterized by very low limits of detection and quantitation: lower than 0.0017 microg/L and good repeatability for all four volatile compounds. This new analytical procedure was identified to be easy, reliable, sensitive, and requires only small amounts of sample. It can constitute a good alternative to well-known procedures based on application of head space and gas chromatography coupled with electron capture detection.