Studies of the uptake and binding of trace metals in fungi. Part II. Arsenic compounds in <i>Laccaria amethystina</i>

Abstract

Abstract Caps of the edible mushroom Laccaria amethystina collected during September and October at forested sites in the vicinity of the town of Domzale in Central Slovenia, Yugoslavia, were found by neutron activation analysis (NAA) and hydride generation to have total arsenic concentrations between 109 and 200 mg As kg −1 (dry mass). The extraction of fresh, frozen or freeze‐dried caps with cold Tris buffer at pH 7.6, or with boiling water, transferred 60–70% of the arsenic into the aqueous phase. Sephadex gel permeation chromatography indicated that the arsenic compounds in these extracts were not associated with proteins or other organic compounds of molecular mass larger than 4000 Dal. Cation‐exchange chromatography coupled with NAA, hydride generation, and reverse‐phase chromatography with arsenic‐specific detection (HPLC ICP) showed that dimethylarsinic acid is the major arsenic compound in the extracts. Methylarsonic acid and arsenate account for no more than 10% each of the total arsenic.