Application of the Liquid-Liquid Extraction Method and Subsequent ICP-MS Detection for Speciation Analysis of Arsenic in Wastewater Samples

The current paper describes a method for determining As(III) and As(V) concentrations inwastewater samples. The approach is based on the extraction of As(III) from water samples using anon-polar organic solvent in a 10-12 M HCl medium. The extract contains As(III), while the raffinatecontains As(V). Distilled water can be used to re-extract As(III) from the organic solvent. ICP-MS wasused to analyze As concentrations in the reextract and the raffinate. The average recovery of arsenicby 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 demonstratedthe selectivity and accuracy of the employed method. The relative error of recovery of the standardAs(III) addition is about 2 %, which is similar to the RSD found under repeatability conditions.