Spectrophotometric determination of methyldopa by oxidative coupling reactions using 2,4 -dinitrophenylhydrazine reagent

Spectrophotometric determination of methyldopa in pharmaceutical formulations

A new, simple, precise, rapid and low-cost spectrophotometric method for methyldopa determination in pharmaceutical preparations is described. This method is based on the complexation reaction of methyldopa with molybdate. Absorbance of the resulting yellow coloured product is measured at 410 nm. Beer’s Law is obeyed in a concentration range of 50 – 200 μg ml methyldopa with an excellent correl...

Spectrophotometric determination of nitrate in polluted water using a new coupling reagent.

Reactions in water: alkyl nitrile coupling reactions using Fenton's reagent.

The coupling reaction of water-soluble alkyl nitriles using Fenton's reagent (Fe(II) and H2O2) is described. The best metal for the reaction is iron(II), and the greatest yields are obtained when the concentration of the metal is kept low. Hydrogen-atom abstraction is selective, preferentially producing the radical alpha to the nitrile. In order to increase the production of dinitrile, in situ ...

Spectrophotometric Determination of Drugs Using Iodine As Analytical Reagent

Six drugs viz., Astemizole, Cisapride, Domperidone, Pantoprazole, Rabeprazole and Trazadone were tested for the formation of charge transfer complexes with Iodine. Each of these drugs turned the violet coloured i.e iodine , in CH2Cl2, to brown and exhibited a new band at 366nm in addition to the original band of iodine at 510nm due to anion of the reagent whose intensity increased with increase...

Spectrophotometric determination of ajmaline and brucine by Folin Ciocalteu’s reagent

A rapid and simple spectrophotometric procedure is described for the determination of ajmaline and brucine. The method is based on the development of blue coloured product due to reduction of tungstate and/or molybdate in Folin Ciocalteu’s reagent (FCR) by ajmaline and brucine in alkaline medium. The colour is stable for more than 48 h. The chromogenic reaction has max at 540 nm with molar abso...