Spectrophotometric Determination of Palladium after Separation by Adsorption of its 2-mercaptobenzothiazole Complex on Microcrystalline Naphthalene

The spectrophotometric determination of trace palladium with 2-mercaptobenzothiazole is described. A stable water-insoluble complex formed from palladium and 2-mercaptobenzothiazole is rapidly and quantitatively adsorbed on microcrystalline naphthalene at pH 4.5. The adsorbed naphthalene crystals are separated from aqueous solution by aspiration, dried in a dryer at about 60℃ and dissolved in dimethylformamide. The absorbance of the solution is measured at 435 nm. The various factors such as wavelength, pH, amounts of reagent and naphthalene, shaking time, standing time and choice of solvents are studied