Using of a new field analysis method to investigate the stability of arsenic and its inorganic species in aquatic systems

The stability of arsenic species in aquatic systems is limited by the possi bilities of chemical and biochemical reactions. Redox reactions and bioalky lation lead to changes of the species ratios. In this work, the stability o f As(III) and As(V) was examined at storage of distilled, de-ionized, and d rinking water at different conditions (refrigerator/room temperature; dayli ght/darkness) and additions (sulfuric acid; ascorbic acid). The determinati on of these species was carried out by a modified spectrophotometric method , suitable for laboratory analysis as well as for field analysis. The resul ts show that chemical oxidation and biochemical reduction can occur Sulfuri c acid is favourable for the stabilization of total arsenic and of the inor ganic species.