Analysis of semi-volatile organic compounds in aqueous samples by microwave-assisted headspace solid-phase microextraction coupled with gas chromatography–electron capture detection

The pretreatment technique of microwave-assisted headspace solid-phase microextraction (MA-HS-SPME) has been developed and studied for the extraction of semi-volatile organic compounds (SVOCs) in aqueous samples prior to chromatographic analysis. The optimum conditions for obtaining extraction efficiency, such as the extraction time, extraction temperature, addition of salts, and the ratio of sample to headspace volume parameters were investigated. Experimental results indicated that the proposed MA-HS-SPME technique attained the best extraction efficiency under the optimized conditions, i.e., irradiation of extraction solution (20 mL aqueous sample in 40 mL headspace vial with no addition of salt) under 30 W microwave power for 30 min at 70 °C. The detection was linear at 1–250 ng/L with correlation coefficient exceeding 0.997. The detection limits obtained were between 0.2–10.7 ng/L, repeatability range from 2 to 15%. Real water samples collected from known sites in southern Taiwan were analyzed using the optimized conditions.