The adsorption of simple trace metal cations on amberlite X-AD-1 and X-AD-2 : A study using a multichannel non-dispersive atomic fluorescence detector with quantitation by batch measurements

Abstract

The macroreticular resins Amberlite XAD-1 and XAD-2 are unsuitable for quantitative studies of trace metal speciation in natural waters since significant amounts of the simple cations of copper, iron and zinc are readily adsorbed by the resins. These cations are not desorbed by methanol although they are eluted by methanolic HCl, methanolic NH 3 and sodium dihydrogen ethylenediaminetetraacetate. The interactions have been studied using Cheminert chromatographic equipment directly coupled to a multichannel non-dispersive atomic fluorescence detector, and the results quantitated by batch measurements using graphite furnace atomic absorption spectroscopy. XAD-2 resin adsorbed more trace metals than XAD-1, and the adsorption capacity could be reducced by methylation. The adsorption of copper and zinc was not strongly dependent on pH, and there were differences in the behavious of XAD-1 and XAD-2 toward compting trace metal ions. Contrary to its usual role in the analysis of natural waters, XAD-2 was capable of removing copper and zinc from acetonitrile, and at least some of this adsorbed metal could be eluted ith distilled, deionized water.