Chemical characterization of polychlorinated biphenyls, -dibenzo-p-dioxins, and -dibenzofurans in technical Kanechlor PCB formulations in Japan

Abstract

Technical polychlorinated biphenyl (PCB) formulations-Kanechlor KC-200, KC-300, KC-400, KC-500, KC-600 and KC-1000-produced in Japan were analyzed for the chemical characterization of PCBs, -dibenzo-p-dioxins (PCDDs), and -dibenzofurans (PCDFs) using high-resolution gas chromatography-high-resolution mass spectrometry (HRGC-HRMS) by isotope dilution technique. The homologue/congener profiles of Kanechlor formulations resembled those of Clophen, Aroclor, and Delor, respectively, from Germany, the United States, and Czechoslovakia. Twenty-seven major PCB congeners contributed 50% (in KC-200) to 69-71% (in KC-600, 1000, and 500) to total PCBs. Average total PCB concentrations were 510,000, 800,000, 830,000, 840,000, 870,000, and 880,000 mug/g in KC-1000 (51%), KC-200 (80%), KC-500 (83%), KC-400 (84%), KC-300 (87%), and KC-600 (88%), respectively. Kanechlors also contained PCDDs and PCDFs (4.3 to 0.35 microg/g) as impurities which were approximately 1/10,000 to the PCB concentrations. Congener characterization and concentrations of PCBs and PCDFs were considerably varied in between Kanechlor formulations. The potential for the emissions of PCDDs and PCDFs from Kanechlor was estimated to be 1.94 kg and 464.4 kg, respectively. The average WHO-toxic equivalent (TEQ) was 16 (KC-500) >12 (KC-400) >10 (KC-1000) >4.1 (KC-600) >3.5 (KC-300) >1.9 (KC-200) on microgTEQ/g. Non- and mono-ortho PCBs were the major contributors to the total TEQ in Kanechlor formulations, whereas the PCDD/DF contribution was <2.0%. The environmental input of TEQs from Kanechlors can be estimated to be between 112 and 941 kg.