UTILITY OF QUERCETIN FOR DETERMINATION OF SOME TERTIARY AMINE AND QUATERNARY AMMONIUM-SALTS

A simple and sensitive spectrophotometric method for the assay of eigh t drugs containing quaternary ammonium or tertiary amine moieties is d escribed. The method is based on the interaction of these drugs with q uercetin after its oxidation with N-bromosuccinimide (as counter ion) to give highly colored ion-pairing complexes extractable with organic solvents. The absorbances of the colored complexes are measured in the range of 528-560 nm. Beer's law is obeyed for the studied drugs in th e range 5-30 mu g ml(-1). The method is successfully applied to the an alysis of the studied drugs in commercial dosage forms.