Application of the liquid-liquid extraction method and subsequent icp-ms detection for speciation analysis of arsenic in wastewater samples

Abstract

The current paper describes a method for determining As(III) and As(V) concentrations in wastewater samples. The approach is based on the extraction of As(III) from water samples using a non-polar organic solvent in a 10-12 M HCl medium. The extract contains As(III), while the raffinate contains As(V). Distilled water can be used to re-extract As(III) from the organic solvent. ICP-MS was used to analyze As concentrations in the reextract and the raffinate. The average recovery of arsenic by the proposed method is 99.6 %. It was calculated as the sum of As(III) and As(V) concentrations. The collected data demonstrated high repeatability. The standard addition procedure demonstrated the selectivity and accuracy of the employed method. The relative error of recovery of the standard As(III) addition is about 2 %, which is similar to the RSD found under repeatability conditions.