Quantitative determination of iron(III) and vanadium (V) by spectophotometric H-point standard addition method

The H-point standard addition method (HPSAM) was applied to spectrophotometric data for simultaneous determination of Fe(III) and V(V) or selective determination of Fe(III) in the presence of V(V). The method is based on the difference absorbance of formed complex between Fe(III) and pyrogallol in two different wavelength at pH=6.5. Fe(III) can be determined in the rang of 0.2-23µgml-1 with satisfactory accuracy and precision in the presence of excess V(V) and most of other metal ions. Under working conditions, the proposed method was successfully applied to the simultaneous determination of Fe(III) and V (V) in several synthetic mixtures with different concentration ratio of Fe(III) and V(V).