Atomic absorption spectrometric determination of Fe(III) and Cr(III) in various samples after preconcentration by solid-phase extraction with pyridine-2-carbaldehyde thiosemicarbazone

Abstract

An atomic absorption spectrometric method for the determination of Fe(III) and Cr(III) after solid-phase extraction of their Schiff-base chelates by a column procedure with Amberlite XAD-4 was developed. A Schiff base, pyridine-2-carbaldehyde thiosemicarbazone (PCTSC), was synthesized and used as a chromogenic reagent for solid-phase extraction of Fe(III) and Cr(III) ions in the column procedure. The influence of various analytical parameters including the amount of solid phase, pH, type of elution solution, volume of sample solution, and flow rate of sample solution on the extraction efficiency of analytes were investigated. The recoveries of Fe(III) and Cr(III) were 99 ± 1 and 98 ± 2%, respectively, at the 95% confidence level under the optimum conditions. Fe(III) and Cr(III) were preconcentrated up to 25-fold. The limit of detection of Fe(III) and Cr(III) are 4.1 and 3.72 µg/L, respectively. The proposed method was applied to the determination of these metal ions in tap water, river water, Ataturk Dam water, and alloy samples. The relative standard deviation and the relative error are lower than 6%.