| An ultrasound/microwave assisted extraction and gas chromatography with electron capture detector（GC/ECD） was developed for the simultaneous determination of seven polybrominated diphenyl ethers（PBDEs）in soil.The influences of several parameters,such as the type and dosage of solvent,microwave power and time of extraction,on the extraction efficiencies were investigated.The optimal operation conditions were as follows：extraction solvent：50 mL n-hexane-acetone（1∶1）,microwave power：90 W,and extraction time：10 min.Under the optimal extraction conditions,good linear relationships were obtained in the concentrations of 10-400 μg·L-1 for all the analytes with correlation coefficients(r2) of 0.999 1-0999 7.The limits of detection were between 0.21 ng·g-1 and 0.63 ng·g-1.The spiked recoveries of PBDEs in soil were between 75％ and 121％ with relative standard deviations （RSDs） of 5.2％-7.8％. The proposed method was applied in the determination of PBDEs in wetland soil samples collected from Chongming Island of Shanghai,in which two PBDEs （e.g.BDE-28 and BDE-47） were found.The results were in agreement with those obtained by the Soxhlet-GC method.With the advantages of simple procedures,good sensitivity and high accuracy,this method could be used for the monitoring of PBDEs in soils. |