Development and validation of HPLC–ICP-MS method for the determination inorganic Cr, As and Sb speciation forms and its application for Pławniowice reservoir (Poland) water and bottom sediments variability study

The optimization of methodology for determination and extraction of inorganic ionic As(III)/As(V), Cr(III)/Cr(VI) and Sb(III)/Sb(V) forms in water and easily-leached fractions of bottom sediments by HPLC–ICP-MS were studied. In paper total concentration of As, Cr, Sb, pH and redox potential were determined. Ions were successfully separated on Dionex IonPac AS7: As(III), As(V), Sb(III), Sb(V) and Dionex IonPac AG7: Cr(III), Cr(VI) with LOD 0.18 μg/L, 0.22 μg/L, 0.009 μg/L, 0.012 μg/L 0.11 μg/L, 0.17 μg/L, respectively. Water and bottom sediments samples were collected monthly from Pławniowice Reservoir, in three-point transects between March and December 2012. In the bottom water predominated As(III) and Cr(III) forms and the highest content of Cr(III) was in the water flowing into the Pławniowice Reservoir. Concentration of Cr(VI) increased in the bottom water in the spring and summer (April–July), while decreasing of the Cr(III) content was associated with the release of Cr(VI) from sediment into the water. Studies have shown that antimony accumulates in reservoir sediments and its reduced form was predominated except May and October–November period when high concentrations of Sb(V) was present. In contrast As(V) was the predominant arsenic form in bottom sediments.