Planning and Optimization of Analytical Methodology for the Determination of Phosphate Ions in Aqueous Samples Using Digital Image Analysis

Abstract

A methodology for analyzing phosphate ions in aqueous samples was developed using digital image processing, by the pentavalent molybdate phosphate complex. An apparatus for image acquisition was built and the data from the RGB channels were converted into analytical signals. The method presents good linearity (R2 = 0.9942) for concentrations of 0.25 to 10 mg L-1. Interday and intraday precision were less than 6.8% and 4.5%, respectively, both in terms of RSD. LOD and LOQ were 0.5 and 1.6 mg L-1, respectively. Accuracy was assessed in terms of recovery in natural water samples, with results between 88.5% and 107%.