Pulsepolarographic determination of 6-benzyl-2-thio-uracil

Polarographic (DPP) activity of 6-benzyl-2-thiouracil (6-benzyl-2-mercapto-4-pyrimidinol, BTU) has been examined in a wide range of pH values and it has been discovered that the number and the height of observed peaks depends on composition of supporting electrolyte and concentration of the thiol. Two different types of signals can be obtained. One of them is controlled by diffusion while the other by adsorption. The procedure for the determination of BTU in pure samples in 0.1 mol.dm-3 sodium hydroxide solution has been worked out. The measurements can be performed in a range 3.10(-4)-3.10(-3) mol.dm-3 of BTU. The detection limit is however lower and reaches 5.10(-6) mol.dm-3. The method has been used in the determination of BTU in an antithyroid drug Basdène.