Determination of trace palladium(II) in water by catalytic decoloring spectrophotometry

In the presence of Triton X-100,the trace palladium(Ⅱ) strongly catalyzes the oxidation reaction of dithizone by H_2O_2 in a buffer solution HAc-NaAc (pH 4.5) while heated in a water bath of 70 ℃,and the decoloring extent of solution behaves a good linear relationship in a certain range of palladium(Ⅱ) concentration.Based on this,a new catalytic decoloring spectrophotometric method for the determination of trace palladium(Ⅱ) has been established.The results showed that the maximum absorption wavelength of decoloring solution was at 420 nm,the detection limit was 4.6×10 -7 g/L and the linear range of palladium(Ⅱ) was 0～40 μg/L.The method has been applied to the determination of trace palladium in water with satisfactory results.