New Polymeric Membrane Electrode for Azithromycin Determination

摘要

A new polymeric membrane electrode has been developed for the determination of azithromycin.The electrode was constructed by incorporating the azithromycin-tetraiodomercurate ion pair complex into a polyvinylchloride matrix plasticized by nitrobenzene.This sensor exhibited good linear response (-29.8 mV/ decade) over the concentration range 1.0 x 10~(-2)-7.0 x 10~(-6)M,using a mixed solution as supporting electrolyte containing phosphate buffer (pH = 6.5;I = 0.1 M) and acetonitrile (3:1,v/v).The pH did not affect the electrode performances within the pH range 2-8.Interferences from species such as pharmaceutical excipients are negligible.In order to assess the performance and reliability of the analytical results,the proposed potentiometric method using this selective electrode to azithromycin has been validated.The validated method was successfully applied,using direct potentiometry,to the quantitation of azithromycin in pharmaceutical preparation (rsd=0.87%;mean recovery = 99.5%) and in dissolution profile studies of tablets.