Solvent extraction studies of addition compounds of metal halides and triphenylphosphine, -arsine and -stibine : Detection of palladium

Palladium, is very efficiently extracted as PdI₂·₂(C₆H₅)₃Sb from weakly acidic medium, containing excess of iodide with a solution, of triphenylstibinc in cyclohexane. A test for the detection of palladium is described based on this property. In the presence of sulfite and in the absence of cyanide, which inhibits the reaction, the test is specific. A pink to red color develops in the organic layer enabling the identification of as little as 0.07 μg- Pd.