GC-MS Determination of Polycyclic Aromatic Hydrocarbons in Soil After Solvent Extraction Separation with co-assisted Ultrasonic and Microwave Techniques

Ultrasonic and microwave techniques were applied in combination to the extraction of traces of polycyclic aromatic hydrocarbons (PAHs) from soil sample using mixture of n-hexane and dichloromethane (1+1) as solvent.The extract,after dehydration and concentration,was used for GC-MS determination of the PAHs.When the moisture content and inorganic salt content of the soil sample were 10% and 6% respectively,and under working conditions of ① using 40 mL of the mixed solvent,② power of microwave radiation 100 W,③ power of ultrasonic vibration 50 W and ④ time of extraction 9 min,the recovery obtained in the analysis of simulated samples attained to 86.9%,and average values of RSD′s (n=5) found was 3.6%.As compared with several other methods of extraction,including the soxhlet extraction,open or closed vessel microwave assisted extraction and direct or indirect ultrasonic agitation extraction,the present method was proved to have higher capacity and efficiency as well as better repeatability.