Second and First-Derivative Spectrophotometry for Efficient Simultaneous and Individual Determination of Palladium and Cobalt Using 1-(2-Pyridylazo)-2-naphthol in Sodium Dodecylsulfate Micellar Media

Abstract

1-(2-Pyridylazo)-2-naphthol (PAN) has been used for the simultaneous and individual determination of palladium and cobalt at trace levels. PAN complexes of palladium and cobalt at neutral pH form green-color neutral complexes, which are soluble in aqueous SDS micellar media. Under optimum conditions, calibration graphs for individual determinations by zero and first-derivative spectrophotometry, and also for simultaneous determinations by second-derivative spectrophotometry were obtained. A zero-crossing method using second-derivative spectrophotometry at 628 or 578 and 614 nm, respectively, for cobalt and palladium was used for simultaneous determinations. The method is able to determine the cobalt-to-palladium ratio, 5:1 to 1:10 (Wt/Wt), accurately. The accuracy and reproducibility of the determination method for various known amounts of cobalt and palladium in their binary mixtures were tested. The effects of diverse ions on the determination of cobalt and palladium to investigate the selectivity of the method were also studied. The recommended procedures were applied to a synthetic binary alloy, cobalt in vitamin B12 and B-complex ampoules, a Co2O3-Co3O4 laboratorial chemical mixture, some synthetic cobalt-alloy samples, a Pd-charcoal catalyst, and some synthetic palladium alloys.

Zero‐Crossing Second Derivative Spectrophotometry for Simultaneous Determination of Palladium and Nickel Using 1‐(2‐Pyridylazo)‐2‐Naphthol in Mixed Micellar Solutions

“…8 In the previous study an efficient derivative method for the simultaneous determination of palladium and cobalt was established. 9 The satisfactory selectivity for the method was obtained because acidifying of the working solution after complex formation caused decomposition of the other metals-PAN complexes. This present work reports a simple, sensitive and selective method for the simultaneous determination of palladium and nickel by second-derivative spectrophotometry in a mixture of aqueous micellar solution.…”

A new sorbent based on MWCNTs modification for separation/preconcentration of trace amounts of Cd(II), Cr(III), Cu(II), Ni(II), and Pb(II) and their determination by flame atomic absorption spectrometry

“…Therefore, heavy metals are considered as hazardous materials for ecosystems, animals, plants, and human beings. Heavy metals that can be found in vegetables, ground water, and wastewaters are mostly toxic even at a very low concentration, and the determination of heavy metals is one of the targets of analytical chemists (Babel and Kurniawan 2004;Barałkiewicz et al 2010;Eskandari et al 2006;Peker 1999;Turkoglu and Soylak 2005). However, direct determination of heavy metals is often not sensitive enough to determine heavy metal ions in environmental samples because of their low concentrations, which are near or below the detection limit of the instrument, and matrix interferences.…”

Selective extraction and determination of Au(III) by first-derivative spectrophotometry

“…First-derivative spectroscopy using zero-crossing has been applied successfully for simultaneous determination of metal ions in their binary mixture [33][34][35][36][37][38][39]. Toral and Richter [40] developed a spectrophotometric method for the determination of copper and iron in mixtures.…”