title: Unintentional PCB in chlorophenylsilanes as a source of contamination in environmental samples.
abstract: This paper discusses the concentrations and congener patterns of PCBs unintentionally present in chlorophenylsilanes. Chlorophenylsilanes are used in the production of silicone-based adhesives and phenyl silicones. The concentration of PCBs in adhesives was found to range from not-detectable concentrations to 40mg/kg. The concentrations of PCBs in trichlorophenylsilane, dichlorodiphenylsilane, chlorotriphenylsilane, and diphenylsilanediol were 0.00072-2.7, 6.5-1,500, 0.019-1.1, and 0.12-120mg/kg, respectively. Dichlorodiphenylsilane and diphenylsilanediol, in particular, had high PCB concentrations. The PCB concentration of some specimens exceeded the 50mg/kg limit set by the transportation regulations of the Stockholm Convention. In the adhesives and chlorophenylsilanes, mono- and di-chlorinated biphenyls were detected in high proportions. The congeners detected in dichlorinated biphenyls had a structure in which one chlorine atom was substituted at each of the two aryls of the biphenyl backbone. This indicated that the chlorobenzene used for synthesizing chlorophenylsilanes undergoes dimerization. The congener and homologue patterns of the adhesives containing PCBs were similar to dichlorodiphenylsilane and diphenylsilanediol. It was concluded that the production of the adhesives is based on these substances. In addition, these results indicate that silicone-based products may become a source of PCBs in the environment, leading to irregular PCB values in environmental analysis.
authors: Hokkaido Research Organization, Environmental and Geological Research Department, Institute of Environmental Sciences, N19W12, Kita, Sapporo, Hokkaido, Japan. Electronic address: anezaki@hro.or.jp.
authors: Katsunori
authors: K
authors: Anezaki
authors: Center for Advanced Science and Innovation, Osaka University, Osaka, Japan.
authors: Takeshi
authors: T
authors: Nakano
mesh_terms: D000269:Adhesives / Q000032:analysis* / Q000737:chemistry; D011078:Polychlorinated Biphenyls / Q000032:analysis* / Q000737:chemistry; D012821:Silanes / Q000032:analysis*; D012828:Silicones / Q000138:chemical synthesis
chemical_list: D000269:Adhesives; D012821:Silanes; D012828:Silicones; C025250:dichlorodiphenylsilane; C032792:diphenylsilanediol; D011078:Polychlorinated Biphenyls
keywords: Adhesive; Chlorophenylsilanes; Polychlorinated biphenyls; Silicone; Unintentional product