Catalytic Kinetic Spectrophotometric Determination of Trace Palladium (II) with Poniacyl Carmine 2B

A new sensitive and selective catalytic kinetic spectrophotometric method for the determination of trace amount of palladium (II) has been developed. The method is based on the catalytic effects of palladium (II) on the reduction reactions of Poniacyl Carmine 2B (PC 2B) by sodium dihydrogen hypophosphite (NaH₂PO₂) in sulfuric acid medium. The optimal reaction conditions are PC 2B (1.0 times 10^-3 mol/L) 0.8 mL, H₂SO₄ (2.0 mol/L) 1.0 mL, NaH₂PO₂(100 g/L) 3.0 mL and 18 min at 100degC. Under the condition selected, trace amounts of palladium (II) can be determined. The linear ranges are 0.008 - 0.032 mug/mL of Pd(II) with a detection limit of 5.51 times 10^-10 g/mL. the relative standard deviation was less than 4.8 % (n = 11). The coexistent ions are eliminated by preconcentration and separation with sulphydryl dextran gel (SDG). The results were fairly satisfactory. The method has been applied to the determination of Pd(II) in activator samples with satisfactory results.