Determination Of PCBs In Environmental Samples With GC-ECD

The PCBs extraction from the soil samples using microwaveassisted extraction was optimized in this method. And a method for thequalitative and quantitative determination of PCBs was established with aGC-ECD.MAE, ultrasonic assisted extraction (USE) and Soxhletextraction (SE) were compared for the extraction of PCBs in the soilsamples.. The results of the experimentation indicated that MAE was anadvanced method of extraction , and the optimal parameters for MAEextraction were obtained: 110℃of extraction temperature ; 5min ofextraction time ;20mL acetone/hexane(1:1v/v)of extractive solvent .Thepressure and power was 5atm and 800w, respectively. The results showedthat the efficiency of MAE was a little higher than USE for the six PCBs(pcb28, pcb52, pcb101, pcb138, pcb153 and pcb180) .The averagerecoveries obtained by MAE ranged from 95．30% to 98．99% and by USE ranged from 91．35%-96．20%.The studies indicated that MAE was arapid and high efficiency method for PCBs extraction in the soil samples.The co-cleanup techniques of oil of vitriol and silica gelcolumniation were used to eliminate the impurities in the soil samples.The average recoveries obtained by technique of oil of vitriol rangedfrom 96．40% to 99．42% and by technique of silica gel columniationranged from 91．02% to 101．1%.The result demonstrated that theco-cleanup method was useful and effective.The methods have been established for the analysis of PCBs inthe soil using GC-ECD. And the optimal parameters for GC-ECD wereobtained :carrier gas (N₂) :2mL/min; temperature program: 150℃to200℃,at 10℃/min ,1min hold , 200℃to 280℃,at 5℃/min ,2minhold ;injector temperature: 225℃;detector temperature:300℃.Thedetection limits for the six main kinds of PCBs, pcb28, pcb52, pcb101,pcb138, pcb153 and pcb180, were in the range of 2．69×10 (-11) -8．69×10^-11 .And the repeated RSD for these criterion samples ranged from 0．33% to1．05%. It has shown that the precision of this method was high and thedetection limits were low. This method was applied satisfactorily fordetermination of PCBs in the soil samples.Zhang Zhuo(Applied Chemistry)Supervised by Shao Chaoying...