An approach by using near-infrared diffuse reflectance spectroscopy and resin adsorption for the determination of copper, cobalt and nickel ions in dilute solution

摘要

Near-infrared spectroscopy (NIRS) has been proved to be a powerful analytical tool and used in variousfields, it is seldom, however, used in the analysis of metal ions in solutions. A method for quantitativedetermination of metal ions in solution is developed by using resin adsorption and near-infrared diffusereflectance spectroscopy (NIRDRS). The method makes use of the resin adsorption for gathering the ana-lytes from a dilute solution, and then NIRDRS of the adsorbate is measured. Because both the informationof the metal ions and their interaction with the functional group of resin can be reflected in the spec-trum, quantitative determination is achieved by_using multivariate calibration technique. Taking copper(Cu~(2+)), cobalt (Co~(2+)) and nickel (Ni~(2+)) as the analyzing targets and D401 resin as the adsorbent, partialleast squares (PLS) model is built from the NIRDRS of the adsorbates. The results show that the concen-trations that can be quantitatively detected are as low as 1.00, 1.98 and 1.00 mg L~(-1) for Cue~(2+), Co~(2+) andNi~(2+), respectively, and the coexistent ions do not influence the determination.