Determination of 2′,3′‐Dideoxyinosine Using Iron (II) Phthalocyanine Modified Carbon Paste Electrode

Abstract

An amperometric sensor, based on carbon paste impregnated with iron (II) phthalocyanine complex (FePc), has been constructed for the assay of anti‐HIV agent dideoxyinosine (didanosine, DDI). Using chronoamperometry (E = +1.04 V versus Ag/AgCl) technique, the amperometric sensor can be used reliably for dideoxyinosine assay at pH 7.4 phosphate buffer in the 1.5–9.5 nmol/L concentration range with a detection limit of 5.7 × 10⁻¹⁰ mol/L. The surface of the electrode can easily be regenerated by simple polishing, obtaining a fresh surface ready for use in a new assay. The new amperometric sensor proved to be highly reliable for the assay of dideoxyinosine purity in raw material as well as for the uniformity content test of Videx^® tablets.

Keywords:

• Amperometric sensor
• Iron (II) phthalocyanine
• 2′,3′‐Dideoxyinosine

Acknowledgments

The authors thank the National Research Foundation of South Africa and Claude Harris Leon Foundation for their financial assistance.