Selective pyrimidinethiols for palladium(II) determination

Alkyl and aryl substituted 4, 4, 6-trimethyl-(1H, 4H)2-pyrimidinethiols react selectively with palladium(II) in strong acids, forming yellow complexes (lambda(max) 430 nm) extractable into non-polar solvents. By an extractive spectrophotometric procedure, microgram amounts of palladium may be determined in the presence of milligram amounts of many species, including all the other platinum-group metals.