Confirmation of Arsenate, Arsenite, Methylarsonate and Dimethylarsinate in an Aqueous Extract from a Brown Seaweed, Hizikia fusiforme

Abstract

An aqueous extract from a brown seaweed, Hizikia fusiforme, was partially purified by benzene-extraction after being treated with alcohol for removal of polysaccharides. The extract was then subjected to strong-acid cation-exchange chromatography which consisted of a sercial connection of two columns of AG 50W×12. There arsenic fractions corresponding to the reference arsenate, arsenite and methylarsonate were obtained by elution of the column, with _M/20 hydrochloric acid. Elution of the short column, taken apart from the long column, with 1.5_M aqueous ammonia gave an additional arsenic fraction corresponding to the reference dimethylarsinate. These fractions were chromatographed on cellulose thin layer with a variety of solvent systems after being purified by gel filtration chromatography on Bio Gel P-2. By the t.l.c and co-t.l.c with the reference arsenicals, they were confirmed to be arsenate, arsenite, methylarsonate and dimethylarsinate, respectively.