Spectrophotometric determination of arsenic in biological tissues and sediments after digestion with nitric, sulphuric and perchloric acids and pre-concentration by zinc column arsine generation and trapping.

Abstract

A procedure for the determination of total arsenic in environmental extracts is described. Arsenic is converted into arsine using a zinc reductor column, the evolved arsine trapped in a potassium iodide - iodine solution and the arsenic determined spectrophotometrically as an arsenomolybdenum blue complex. The detection limit (based on four times the standard deviation of six blank measurements) is 0.024 µg and the coefficient of variation is 5.1% at the 0.1-µg level. The method is free from interferences by other elements at levels normally found in environmental samples.