Electronic signal derivation to improve the performance of kinetic methods of analysis

Abstract

Kinetic methods of analysis based on the electronic derivation of absorbance kinetic curves with respect to time were developed. The bromate oxidation of pyridine-2-aldehyde 2-pyridylhydrazone (PAPH) and the hydrogen peroxide oxidation of iodide, both showing a Landolt effect, were used as indicator reactions. The analytical performance of the electronic derivation approach was evaluated in the determination of iodide, bromide, iron(II), molybdenum and tungsten. Improvements in precision, accuracy and limit of detection are the main advantages of the approach over conventional rate and induction period methods. The selectivity of the kinetic-based analytical measurements is not degraded by electronic derivation and the inherent simplicity of the analysis is maintained. Electronic derivation of the original kinetic curve provides additional analytical information which can be used with advantage for multi-component analysis.