微波萃取土壤中PAHs的研究

Microwave assisted Extraction of PAHs from Soils

研究了ＭＫ－１型光纤压力自控微波溶样系统用于微波萃取的可行性．以合成土样为对象，比较系统地研究了微波萃取ＰＡＨｓ的条件、萃取效率以及溶剂、水分、土壤基体物质等因素的影响．在微波作用下丙酮－正己烷（体积比为１∶１）和二氯甲烷对ＰＡＨｓ的萃取能力相近；试样中小于２０％的水分使丙酮－正己烷（体积比为１∶１）的萃取能力提高，而水分高于５％则使二氯甲烷的萃取能力略有降低．在选定条件下，萘、苊烯、芴、菲、蒽、、苯并（ａ）芘的回收率在８２．２％～９４．１％之间．

The procedure of microwave assisted extraction(MAE) of PAHs from synthetic soil samples has been studied with a MK 1 pressure automatically controlled sample dissolving system. The digestion vessels coupled with this system were improved to suit to MAE. The optimum parameters for MAE of PAHs from soil have been studied in detail. Experimental results show that the MAE efficiency was influened by the solvent type, the microwave radiation time and the soil moisture and matrix. It was found that the MAE efficiency obtained by using acetone hexane(volume ratio 1∶1) was some equal to by using dichloromethane. The optimum MAE conditions for 2 g dry sample are as follows: adding water to 15% moisture, then adding 30 mL acetone hexane(volume ratio 1∶1), microwave power being at 600 W, pressure at the first stage(0 1￣0 5 MPa) and microwave heating for 6 min. The extracts were detected by HPLC. The recoveries of naphthalene, acenaphthylene, fluorene, phenanthrene, anthracene, chrysene and benzopyrene were in the range of 82 2%—94 1%. Compared with the classical Soxhlet extraction, MAE is a more efficient, time saving and solvent saving method.