Spectral Estimation Of Methyldopa By The Oxidative Coupling Method Using A Benzidine Reagent

Abstract

The study included the development of a spectrophotometric method for assessing methyldopa (MDP) in pharmaceutical and pure forms. Based on an oxidative coupling reaction, this process entails oxidizing the medication using sodium periodate (NaIO₄) and combining it with a benzidine reagent in a diluted base medium. The outcome is a water-soluble, orange-colored compound with maximal absorption at 488 nm in wavelength. The concentration range of methyldopa that aligns with the beer law is 1.25–25 µg/mL , the molar absorption coefficient value is 5597.198 L. mol^-1.cm^-1,and the sandellʼs significance value, is 0.038 µg. cm^-2 indicating the sensitivity of the method. The low relative standard deviation of 1.73% indicates that the approach exhibits good precision, the method's detection limit is found to be 0.26 µg/ml, indicating that it can accurately identify methyldopa at such low concentrations. The established technique has been effectively used to examine the presence of methyldopa in tablets. The method's accuracy in identifying the methyldopa content of real-world samples is demonstrated by the reported 100.33% recovery rate for methyldopa in these samples.