Abstract: A method was established for determination of 59 volatile organic compounds (VOCs) in soils by gas chromatography-mass spectrometry with purge-and-trap pretreatment. The effects of pretreatment conditions such as purging temperature, purging time and desorption time were investigated. The detection limits were 0.1-5.0 ng/g, and the recoveries of spiked sample were in the range of 68.7%-128.7% with RSD of 0.9%-12.5% (n=6), indicating that the method is suitable for the analysis of VOCs in soils．From the analysis results of actual petrochemical soil samples, it can be concluded that most of the samples belong to low concentration petrochemical soil samples and can be determined directly by purge-and-trap and gas chromatography-mass spectrometry; Very few high-concentration petrochemical soil samples need to be pretreated by methanol extraction-extraction solution injection; However, in addition to standard methods, it is necessary to develop new analytical methods for soils containing unidentified alkanes, and aromatic hydrocarbons above C9.

Key words: purge-and-trap, volatile organic compounds, soils, gas chromatography-mass spectrometry