Development of analytical methods for some transition metal cations by thin-layer chromatography using alpha-dioximes as complexing agents

Abstract

In this study, separation and quantitative determinations of some transition metal cations by complexing thin-layer chromatography and densitometry were developed. Nickel (II) and palladium (II) were clearly separated from chromium (III), manganese (II), iron (III), cobalt (II) and copper (II) on precoated silica gel layer in hexane, chloroform and ethanol mixed solvent systems containing the alpha-dioximes : dimethylglyosime, benzildioxime, furildioxime or nioxime; as specific complexing agents. The developing solution systems containing various compositions and concentrations of solvents and ligands were investigated and utilized. Quantification of nickel (II) and palladium (II) on the TLC plate by densitometer were also achieved in the concentration of 5 to 80 nanograms. The addition of triethanolamine in the developing solution was attempted to mask interfering metal ions in the binary mixtures and certified reference alloys. Finally, the proposed method developed in this study was applied to the determination of nickel in the certified reference alloys giving a satisfactory result with a relative standard deviation of less than 5 percent and a relative error of less than 1.0 percent.