title: Evaluation of an aqueous KOH digestion followed by hexane extraction for analysis of PCDD/Fs and dioxin-like PCBs in retailed fish.
abstract: Aqueous KOH digestion followed by hexane extraction has been employed in the extraction of dioxins (polychlorinated dibenzo- p -dioxins, dibenzofurans and dioxin-like polychlorinated biphenyls) for biological samples, but there are no reports on its evaluation. Therefore, we report here the evaluation of this extraction for the analysis of dioxins in retailed fish. The effect of the alkaline digestion on dioxins was evaluated by estimation of recoveries. The recoveries of dioxins after the alkaline digestion were good (79-106%) in various kinds of retailed fish except tuna. In tuna, loss of octachlorodibenzofuran (OCDF) was clearly observed, however, the loss was corrected by internal-standard quantification; (13)C12-labeled OCDF was added before the alkaline digestion. Comparative study showed that alkaline digestion followed by hexane extraction provides extraction efficiencies of dioxins equal to those of conventional Soxhlet extraction in fish. Additionally, in analysis of a certified reference fish sample with this extraction, the values obtained for certified isomers were almost equal to the certified values. Since the present method is very simple and inexpensive, it would be useful for analysis of dioxins in retailed fish.
authors.affiliation: Division of Foods, National Institute of Health Sciences, 1-18-1 Kamiyoga, 158-8501 Tokyo, Setagaya-ku, Japan. tutumi@nihs.go.jp
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Tsutsumi
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Amakura
authors.forename: Kumiko
authors.initials: K
authors.lastname: Sasaki
authors.forename: Masatake
authors.initials: M
authors.lastname: Toyoda
authors.forename: Tamio
authors.initials: T
authors.lastname: Maitani
mesh_terms: D000818:Animals; D001572:Benzofurans / Q000032:analysis*; D000072338:Dibenzofurans, Polychlorinated; D005399:Fishes; D005506:Food Contamination / Q000032:analysis*; D006586:Hexanes / Q000737:chemistry*; D006878:Hydroxides / Q000378:metabolism*; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis*; D017680:Potassium Compounds / Q000378:metabolism*; D014867:Water / Q000737:chemistry
chemical_list: D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D006586:Hexanes; D006878:Hydroxides; D000072317:Polychlorinated Dibenzodioxins; D017680:Potassium Compounds; D014867:Water; D011078:Polychlorinated Biphenyls; C029943:potassium hydroxide