title: Investigation of saponification for determination of polychlorinated biphenyls in marine sediments.
abstract: The effects of saponification conditions (temperature and water content of saponifying solution) on the determination of chlorinated biphenyls (CBs) in marine sediments were investigated. Although highly chlorinated biphenyls (nona- to deca-CBs) decomposed during high-temperature saponification, the degree of degradation was reduced by adding water to the ethanolic potassium hydroxide saponifying solution. Room-temperature saponification yielded quantitative recovery of highly chlorinated biphenyl surrogates but low extraction efficiencies of lightly chlorinated biphenyls (mono- to di-CBs). The same samples were analyzed by other extraction techniques, for example, pressurized liquid extraction, and analytical results were compared. The mono- and di-CB concentrations were correlated with the extraction temperatures of various extraction techniques. In particular, the concentrations of some CB congeners (CB11, CB14) were higher with saponification. The low degree of degradation of highly chlorinated biphenyls and the high recovery of lightly chlorinated biphenyls were compatible when room-temperature and high-temperature saponification were combined. Except for the anomalies of CB11 and CB14, the combined method gave satisfactory results for analysis of PCBs.
authors.affiliation: Environmental Standards Section, National Metrology Institute of Japan, AIST, Central 3-10, 1-1-1, Umezono, Tsukuba, Ibaraki 305-8563, Japan. mas-numata@aist.go.jp
authors.forename: Masahiko
authors.initials: M
authors.lastname: Numata
authors.forename: Takashi
authors.initials: T
authors.lastname: Yarita
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Aoyagi
authors.forename: Misako
authors.initials: M
authors.lastname: Yamazaki
authors.forename: Akiko
authors.initials: A
authors.lastname: Takatsu
mesh_terms: D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis*; D019015:Geologic Sediments / Q000737:chemistry*; D011078:Polychlorinated Biphenyls / Q000737:chemistry*; D012503:Saponins / Q000032:analysis*; D012995:Solubility; D013696:Temperature
chemical_list: D004785:Environmental Pollutants; D012503:Saponins; D011078:Polychlorinated Biphenyls