Determination of PCBs in tetrachlorinated quinone using gas chromatography with electron capture detection.

A simple, sensitive method for determining polychlorinated biphenyl (PCB) congeners in industrial product 2,3,5,6-tetrachloro-1,4-benzoquinone with GC/ECD detection has been developed. The method based on liquid-liquid extraction from tetrachlorinated quinone dissolved in N,N-dimethylformamide was found to be efficient for the determination of the levels of the investigated pollutants. A series of extraction and purification steps were designed for the sample pretreatment. The congener specific averages of recoveries were 82-96% for Aroclor 1242 and 1254 at a total spiking level of ca. 0.4 mug g(-1) sample. The reproducibilities of replicate determinations of different congeners were typically 5-19% except one with the average 13% R.S.D. (n=3). This method was applied to evaluate the background levels of PCBs in tetrachloro-1,4-benzoquinone, of which the corresponding PCB levels varied from 0.014 to 1.5 mug g(-1).