Extraction Spectrophotometric Determination of Micro Amounts of Palladium(II) with 2,4-Dihydroxy Acetophenonethiosemicarbazone

Abstract

2,4-Dihydroxy acetophenonethiosemicarbazone is used as a chromophoric

reagent for the extraction and spectrophotometric determination of

palladium(II). Palladium(II) forms 1 : 1 and 1 : 2 complexes with the reagent

in acetic acid-sodium-acetate buffer of pH 3.5. The 1 : 1 and 1 : 2

complexes have λ_max at 375 nm and 390 nm respectively. Palladium(II) is

qualitatively extracted from aqueous phase using 4-fold molar excess of

reagent and the complex is stable for 48 h. Beer's law is obeyed in the

range of 0.7 to 12.0 ppm and molar absorptivity of the complex is

1.3 x 10⁴ lit mol^–1 cm^–1. The effect of various foreign ions is also studied.

The method is applied for the estimation of micro amounts of palladium(II)

in synthetic mixtures having typical palladium-alloy composition.