USE OF PALLADIUM(II) CHLORIDE AS COLOR-FORMING REAGENT IN SPECTROPHOTOMETRIC DETERMINATION OF PROPYLTHIOURACIL IN AQUEOUS-SOLUTION AND TABLETS

It has been established that propylthiouracil reacts with palladium(II ) choloride in Britton-Robinson buffer solutions in the pH range 2.16- 5.50 and forms a water soluble complex with maximum absorbance at 325 nm. By using different spectrophotometric methods it was found that th e composition of the complex of propylthiouracil and palladium(II) was 1:1. The molar absorptivity at 325 nm is 5.85 x 10(3) l mol(-1) cm(-1 ) at pH 5.08. Beer's law is obeyed up to 80 mu mol/l propylthiouracil concentration. The detection limit of the method is 0.41 mu g ml(-1). The relative standard deviation (n = 7) varies over the range 0.166-0. 35%. The proposed method was found to be suitable for accurate and sen sitive analysis of propylthiouracil in aqueous solution and propiltiou racil tablets.