Catalytic spectrophotometric determination of trace palladium(II) in mineral samples based on the oxidation of potassium bromate on dithizone

In the presence of TritonX-100,the trace palladium(Ⅱ) strongly catalyzes the oxidation reaction of dithizone by KBrO3 in the medium of H3PO4 and heating in the water bath of 80 ℃ and the decoloring extent of solution with palladium(Ⅱ) concentration behaves a good linear relationship.Based on this,a new catalytic decoloring spectrophotometric method for the determination of trace palladium(Ⅱ) is established.The results show that the maximum absorption wavelength of decoloring solution is at 410 nm,the detection limit is 4.42×10-7 g/L and the linear range of palladium(Ⅱ) is 0-60 μg/L.The method has been applied to the determination of trace palladium in mineral samples with the RSD of less than 4%,and the recovery of 98.6%-102.0%.