Determination of Petroleum Hydrocarbons in Soil by GC Combined with Ultrasonic Extraction

A method was established for the determination of 33 petroleum hydrocarbons from C8 to C40 in soil by gas chromatography with flame ion detector after ultrasonic extraction with a probe ultrasonic generator. The effect of extraction solvent and its dosage, ultrasonic time and extraction times on extraction efficiency for petroleum hydrocarbons in soil was investigated by orthogonal experiments, giving the optimized condition was as follow:10.00 g of sample was extracted ultrasonically with 30 mL of dichloromethane as extraction solvent for 10 min and 2 times. Linearity ranges of 33 petroleum hydrocarbons were within 500 mg·L^-1 and detection limits (3s) were 0.10-0.40 mg·L^-1. Recovery rates obtained by standard addition method were in the range of 83.2%-106% and RSDs (n=7) were in the range of 0.80%-5.5%.