Isolation and Identification of Arsenobetaine from Concentrated Extracts of Skipjack Tuna Euthynnus pelamis and Albacore Thunnus alalunga

Abstract

The water-soluble arsenic compound was isolated from a concentrated extract of skipjack tuna (so-called “katsuo-senji” in Japanese) which was prepared from cooker drain of “katsuo-fushi” preparation, and that of albacore prepared from steaming drain of tuna canning. The specimens were extracted with a chloroform-methanol mixture, and the arsenic compounds were isolated from the methanol phases by successive chromatographies on active carbon, Dowex 50W-×8 (H⁺form), Dowex 1-×8 (OH^-form), Sephadex G-25F, Dowex 50W-×2 (pyridinium form), and finally preparative thin layer of cellulose. Both isolated compounds were identified to be arseno-betaine by comparison of TLC behavior, IR and FAB mass spectra with those of synthetic arseno-betaine.