Quantitative kinetic determination of Sb(V) and Sb(III) by spectrophotometric H-point standard addition method

The H-point standard addition method (HPSAM) was applied to kinetic data for simultaneous determination of Sb(V) and Sb(III) and also selectively determines Sb (V) in the presence of Sb(III). The method is based on the differences between rate of complexation of pyrogallol red with Sb(V) and Sb(III) at pH=2. Sb(V) can be determined in the range of 0.3–2.0 (mu)g ml^-1 with satisfactory accuracy and precision in the presence of excess Sb(III). Good selectivity was obtained over the variety of metal ions. The proposed method was used for determination of Sb(V) and Sb(III) in river and spring water samples.