Kinetic-spectrophotometric determination of palladium in hydrogenation catalyst by its catalytic effect on the oxidation of pyrogallol red by hydrogen peroxide

A new kinetic-spectrophotometric method is described for the determination of ultra trace amounts of Pd(II). The methods based on catalytic action of Pd(II) on the oxidation of pyrogallol red (PGR) with hydrogen peroxide at pH 9.7. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of the PGR at 540 nm, for the first 4.5 min from initiation of the reaction. Calibration curve was linear in the range of 0.02-1.00 mug ml(-1) Pd(II). The limit of detection is 0.017 mug ml(-1) Pd(II). The relative standard deviation (R.S.D.) for ten replicate analyses of 0.03 and 0.60 mug ml(-1) Pd(II) was 1.5 and 0.9%. respectively. The influence of more than 40 potential interfering ions was studied for the selectivity. The proposed method was used for the determination of palladium in catalytic material. (C) 2002 Elsevier Science B.V. All rights reserved.