Author : A. Sayhood, Aayad
journal of kerbala university,
Volume 4, Issue 4, Pages 226-234
A simple and accurate spectrophotometric method for the determination of capoten is applied. The procedure is based on the chelate formation with nickel(II) in acidic buffer medium. The complex has a maximum absorption at 617 nm. The optimum conditions for the complex formation were ascertained and the method was developed for the determination of capoten in the concentration range of (20–60) mg/L. The empirical formula of the formed complex was determined, by applying different spectrophotometric methods, at optimum pH of (3-5) and an ionic strength of µ equal to 0.5 M. The stoichiometric ratio was found to be 2:1 of Capoten-Nickel (II) complex as calculated by continuous variations and the mole ratio methods. The continuous variations method was applied for the determination of the conditional stability constant of the formed red complex and was found to be 3.27x107. The proposed method was found to be suitable for the determination of capoten in pure form and in its commercial tablets.