微波萃取土壤中PAHs的研究

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-正已烷(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、(出)、苯并(a)芘的回收率在82.2%～94.1%之间.

Microwave-assisted Extraction of PAHs from Soils

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 MAEof PAHs from soil have been studied in detail. Experimental results show that the MAEefficiency was influened by the solvent type, the microwave radiation time and the soil moisture and matrix. It was found that the MAEefficiency obtained by using acetone-hexane(volume ratio 1:1) was some equal to by using dichloromethane. The optimum MAEconditions for 2 g dry sample are as follows: adding water to 15% moisture, then adding 30 mLacetone-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, MAEis a more efficient, time-saving and solvent-saving method.