4-(N,N-diethylamino) benzaldehyde thiosemicarbazone in the spectrophotometric determination of palladium

Abstract

4-(N,N-diethylamino)benzaldehyde thiosemicarbazone(DEABT) is proposed as a sensitive and selective analytical reagent for the spectrophotometric determination of palladium(II). The reagent reacts with palladium (II) in a potassium hydrogen phthalate-hydrochloric acid buffer of pH 3.0, to form a yellow complex. Beer's law is obeyed in the concentration range up to 3.60 ?gmL-1. The optimum concentration range for minimum photometric error as determined by Ringbom plot method is 0.36-3.24 ?g mL-1. The yellow Pd(II)-DEABT complex shows a maximum absorbance at 408 nm, with molar absorptivity of 3.33 104 dm3 mol-1 cm-1 and Sandell's sensitivity of the complex from Beer's data, for D=0.001, is 0.0032 ?g cm-2. The composition of the Pd(II)-DEABT complex is found to be 1:2 (M:L). The interference of various cations and anions in the method were studied. The proposed method was successfully used for the determination of Pd(II) in alloys, catalysts, complexes and model mixtures with a fair degree of accuracy.