Micellar thin-layer chromatography of coinage metal cations

Abstract

Chromatography of some metal cations has been performed on silica gel layers with micellar mobile phases containing sodium dodecyl sulfate (SDS), an anionic surfactant. The effects on the mobility of metal ions of SDS concentration, mobile phase pH, and the presence of amino acids (l-arginine, dl-phenylalanine, l-tryptophan, and l-histidine) in the mobile phase were examined. Although amino acids caused diffusion (or tailing) of the metal ion spots, use of l-histidine or l-tryptophan facilitates the analytically important separation of a mixture of Au 3+ , Cu 2+ , and Ag + ions. The TLC system comprising silica gel G as stationary phase and 0.01 m SDS (pH 2.3)-0.01 m l-tryptophan or l-histidine, 1 + 9, as mobile phase was identified as the most suitable for the separation of mixtures of Au 3+ , Cu 2+ , and Ag + . The interference of impurities such as amines, phenols, and inorganic anions on the mobility and separation of a mixture of Au 3+ , Cu 2+ , and Ag + ions was also examined. The lower limit of det...