Synthesis of 13C‐labeled polychlorinated biphenyls

Abstract Methods are described for the synthesis of 4‐chloro(1prime;,2prime;,3prime;,4prime;,5prime;,6′‐13C6)biphenyl; 3,3′,4,4′‐tetrachloro(13C12)biphenyl; and 2,2′,3,3′,5,5′,6,6′‐octachloro(13C12)biphenyl; decachloro(13C12)biphenyl from (13C6)benzene of ≧ 99 atom % isotopic purity, on scales of 100 mg to 1 g. The gas chromatographic retention time of each 13C‐polychlorinated biphenyl (PCB) matched that of the corresponding unlabeled commercial reference standard, and the mass spectrum of each compound was consistent with an isotopic purity of ≧ 99 atom % 13C. These compounds are useful as recovery surrogates and internal standards in the determination of PCBs in a variety of complex matrices.