Determination of petroleum hydrocarbons(C10-C40)in soil by gas chromatography with pressurized fluid extraction and fully automatic solid-phase extraction instrument magnesium silicate column purification
A method of determination of petroleum hydrocarbons(C10-C40)in soil by gas chromatography with pressurized fluid extraction and fully automatic solid-phase extraction instrument magnesium silicate column purification was established.About 10 g of diatomaceous earth was added to the freeze-dried 10.0 g soil sample,mixed well and ground,then placed it into a pressurized fluid extractor.The mixture of acetone and n-hexane(volume ratio was 1∶1)was used as the extraction solvent,static extraction was carried out at temperature of 100℃and pressure of 6.895 MPa,with two cycles of extraction.The extracted solution was purified by fully automatic solid-phase extraction instrument after being concentrated by nitrogen blowing.The magnesium silicate purification column was rinsed with 10 mL mixed solution of dichloromethane and n-hexane(volume ratio was 1∶4),and the effluent was collected.After concentration,it is determined by gas chromatography and quantified by external standard method.The mass concentration of petroleum hydrocarbons(C10-C40)had a good linear relationship with the chromatographic peak area in the range of 7.75-1 550 mg/L,with the correlation coefficient of 0.999 8.When the sample was 10.0 g,the detection limit of the method was 5.9 mg/kg,and the quantification limit was 23.6 mg/kg.The average recoveries of spiked samples at low,medium,and high levels were 92.5%-102.0%,and the relative standard deviations of the determination results was 3.2%-6.8%(n=6).This method is suitable for the determination of petroleum hydrocarbons in large quantities of soil samples.
万方数据
