A Mangrove plants Kandelia Candel pigment was applied in the catalytic spectrophotometry.In dilute sulphuric acid medium,Kandelia Candel pigment discolored in the oxidization reaction with potassium periodate catalyzed by Pd(Ⅱ),and the discoloring extent of solution with Pd(Ⅱ) concent behaves the linear relationship.By which,a new catalytic spectrophotometry for the determination of trace palladium(Ⅱ) was established.The linear range is 0～78μg·L-1 and the detection limit is 4.95×10-9g·mL-1 in this method.This method was applied in the determination of trace palladium in palladium-catalyst with the recovery in the range of 99.5%～105.6% and the RSD in the range of 1.89%～2.43%.
