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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Chemiluminometric determination of ascorbic acid in pharmaceutical formulations exploiting photo-activation of GSH-capped CdTe quantum dots

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Sasaki, M. K. [1] ; Ribeiro, D. S. M. [2] ; Frigerio, C. [2] ; Prior, J. A. V. [2] ; Santos, J. L. M. [2] ; Zagatto, E. A. G. [1]
Total Authors: 6
[1] Univ Sao Paulo, NAPTISA Ctr Nucl Energy Agr, Piracicabe - Brazil
[2] Univ Porto, Fac Pharm, REQUIMTE Dept Chem Sci, P-4100 Oporto - Portugal
Total Affiliations: 2
Document type: Journal article
Source: LUMINESCENCE; v. 29, n. 7, p. 901-907, NOV 2014.
Web of Science Citations: 7

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 x 10(-7) to 5.0 x 10(-6) mol/L ascorbic acid (r = 0.9967, n = 5) was attained, with a detection limit of 3.05 x 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 < +/- 4.3%, n = 7). Copyright (C) 2014 John Wiley \& Sons, Ltd. (AU)

FAPESP's process: 11/14413-0 - Comparison of flow analyzers with laminar or pulsed flows and immobilized reagents: application to samples of pharmaceutical, agronomical and/or environmental relevance
Grantee:Milton Katsumi Sasaki
Support Opportunities: Scholarships in Brazil - Doctorate