Reactions of palladium(II) and rhodium(III) with pyridylazo-2-naphthol and dithizone on PANV–KU-2 and PANV–AV-17 fibrous materials

Abstract

Reactions of palladium(II) and rhodium(III) with dithizone (DT) on polyacrylonitrile fiber filled with an AV-17 anion exchanger (PANV–AV-17) and 1-(2-pyridylazo)-2-naphthol (PAN) immobilized on polyacrylonitrile fiber filled with a KU-2 cation exchanger (PANV–KU-2–PAN) are studied by diffuse reflection spectroscopy. Conditions of rhodium complexation on PANV–KU-2–PAN (ascorbic acid concentration, pH of solution in adsorption, and the duration of heating samples) and palladium complexation with DT after adsorption from a 0.1 M NaCl solution (pH 2) on PANV–AV-17 in the dynamic mode are found. The limits of detection for rhodium and palladium are 10 and 5 ng/mL, respectively. At 640 nm, the calibration graphs are linear in the ranges of palladium and rhodium concentrations 0.008–0.06 µg/mL and 0.02–0.2 µg/mL, respectively. The mutual influence of rhodium and palladium is studied. It is shown that the determination of palladium with DT on a PANV–AV-17 solid phase is not affected by the presence of a 5-fold amount of rhodium, and rhodium can be determined on PANV–KU-2–PAN at 590 nm in the presence of 2-fold amounts of palladium.