Speciation analysis of inorganic form of arsenic in ground water samples by hydride generation atomic absorption spectrometry with insitu trapping in graphite tube

This paper presents the results of a study on the optimization of the determination of total arsenic and its species using the absorption atomic spectrometry method combined with hydride generation and in-situ concentration on the inner walls of the graphite tube. To ensure a maximum efficiency of the in-situ analyte concentration on the graphite tube walls, a palladium modifier subjected to preliminary thermal reduction was used. The limits of detection (3σ) were 0.019 ng/mL for total As and 0.031 ng/mL for As(III) at the preliminary analyte concentration for 60s. The optimised procedure of the analyte concentration on the inner walls of the atomiser (graphite tube) was applied for determinations of arsenic in samples of ground water. The content of arsenic in the samples studied varied from 0.21 ng/mL to 0.80 ng/mL for As(III), and from 0.19 ng/mL to 1.24 ng/mL for As(V).