Determination of PCBs in Soil by Automated Headspace Solid Phase Microextraction-GC-MS

Objective To establish a method based on automated headspace solid phase microextraction (SPME)-gas chromatography-mass spectrometry (GC-MS) for the determination of 18 polychlorinated biphenyls (PCBs) in soil.

Methods Through analyzing the effects of soil amount to be sampled, water volume to be added, extraction temperature, and extraction duration on the enrichment of SPME, we identified the optimal conditions as following: adding 6 mL of purified water into 4 g of soil sample, followed by extraction at 70 ℃ for 30 min.

Results A good linear relationship was observed in the range of 250-2 500 pg/g. The detection limit was 20-50 pg/g. The recovery rate ranged from 90.2% to 125.5%, and relative standard deviation was from 1.58% to 9.91%.

Conclusion Combining the advantages of fast, convenient of SPME and precise, and accurate of GC-MS, this method is particularly suitable for rapid screening analysis of trace PCBs in soil.