Studies on the Compounds Related to PCB (V)

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Our earlier study revealed that unknown organochlorinated compounds, which were mainly composed of polychlorinated quaterphenyl (PCQ), were present largely in Kanemi rice oil caused the “Yusho.”In this report, in order to determine PCQ in Kanemi rice oil, a simple analytical method for PCQ was established and PCQ standard was prepared.The actual PCQ level in the oil was 490 to 866ppm, equivalent to 0.88-3.46 times more than the actual PCB level found in the oil.Moreover, the chlorine concentration of PCQ in the oil was 207 to 450ppm by MCDGC. From this result, it was confirmed that PCQ occupied 72-89% of the unknown in the oil.In addition to clarify the cause why large quantities of PCQ was present in the oil, Kanechlor 400 (KC-400), which had been used as the thermotransfer media, was analysed for PCQ. Consequently, it became clear that PCQ had generated at level of 690-31, 000ppm in the thermotransfer media.Therefore, it was investigated whether PCQ would be generated thermochemically from PCB.KC-400, Japanese commercial PCB preparation containing 48% chlorine, was poured in a glass ampoule. After the ampoule was sealed, it was heated under various conditions. Consequently, it was confirmed that PCQ was generated thermochemically from KC-400 by heating KC-400 at high temperature in a glass ampoule. The PCQ level in KC-400 increased by heating KC-400 at higher temperature and during longer period. Moreover, it was clear that the PCQ formation was more accelerated by heating under the presence of stainless steel and water, and consequently the PCQ concentration in heated KC-400 became the maximum level, 47, 000ppm.