COULOMETRIC TITRATION OF HYDROXYUREA

Hydroxyurea, HXU, is quantitatively determined by electrochemically ge nerated bromine. The overall reaction between HXU and Br-2 is studied and determined to be NH2CONHOH + Br-2 + 1/2H(2)O --> HBr + NH4Br + CO2 + 1/2N(2)O. The titrations are performed in the monotonic consecutive mode with the use of a nonisolated counter electrode. The end point i s detected amperometrically (with a gold or platinum indicating electr ode) or potentiometrically (with a gold indicating electrode). The che mical composition of the solution is 0.4 M KBr in acetate buffer. Conc entrations of HXU in the range from 5 mM to 0.1 mM are determined with a standard deviation of 1-2%, respectively. (C) 1997 Academic Press.