Determination of arsenic(V) and arsenic(III) species in environmental samples by coprecipitation with zirconium hydroxide and pre-atomization atomic absorption spectrometry

Abstract

A method for the determination of ultra-trace amounts of arsenic species in environmental aqueous samples is presented. This method initially involved coprecipitation of arsenic(III) and arsenic(V) with zirconium hydroxide. Subsequent investigations have been made of the volatilization of arsenic(III) based on the conversion of trivalent arsenic in solution into low-boiling arsenic trichloride by concentrated hydrochloric acid. By means of different temperature programmes, arsenic(III) can quantitatively be removed from a graphite tube coated with zirconium, while arsenic(V) quantitatively remains in the furnace up to a temperature of 1400 °C. The recoveries from environmental samples are satisfactory.