Chemiluminometric determination of ascorbic acid in pharmaceutical formulations exploiting photo‐activation of GSH‐capped CdTe quantum dots. (3rd March 2014)

• Record Type: Journal Article
• Authors: Sasaki, M. K.; Ribeiro, D. S. M.; Frigerio, C.; Prior, J. A. V.; Santos, J. L. M.; Zagatto, E. A. G.
• Is Part Of: Luminescence. Volume 29:Number 7(2014)
• Page Start: 901
• Page End: 907
• Publication Date: 2014-03-03
• Subjects: Luminescence -- Periodicals; Bioluminescence -- Periodicals; Chemiluminescence -- Periodicals; Luminescence -- Periodicals; 535.35
• DOI: 10.1002/bio.2639
• Languages: English
• ISSNs: 1522-7235

Abstract

<abstract abstract-type="main"> <title>ABSTRACT</title> <p>An automated multi‐pumping flow system is proposed for the chemiluminometric determination of ascorbic acid in pharmaceutical formulations, relying on the ability of semiconductor nanocrystals to generate short‐lived reactive species upon photo‐irradiation. A photo‐unit based on visible‐light‐emitting diodes is used to photo‐excite cadmium telluride (CdTe) quantum dots capped with glutathione, leading to the generation of radicals that react with luminol under alkaline conditions, yielding the chemiluminescence. Ascorbic acid acts as a radical scavenger, preventing the oxidation of luminol, thus ensuring a concentration‐dependent chemiluminescence quenching. After system optimization, a linear working range of 5.0 × 10^‐7 to 5.0 × 10^‐6 mol/L ascorbic acid (<italic>r</italic> = 0.9967, <italic>n</italic> = 5) was attained, with a detection limit of 3.05 × 10^‐7 mol/L and a sampling rate of 200/h. The flow system was applied to the analysis of pharmaceutical formulations and the results were in good agreement with those obtained by the reference titrimetric procedure (RD &amp;#60; ± 4.3%, <italic>n</italic> = 7). Copyright © 2014 John Wiley &amp; Sons, Ltd.</p> </abstract>