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

• Type: Article in International Scientific Journal
• Date: 2014

Authors

Sasaki, MK (Author) Other; Ribeiro, DSM (Author) Other; Frigerio, C (Author) Other; Prior, JAV (Author) FFUP; Santos, JLM (Author) FFUP; Zagatto, EAG (Author) Other

Journal

Title: Luminescence

Vol. 29

Pages: 901-907

ISSN: 1522-7235

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 12 Citations

Scopus - 14 Citations

Scientific classification

FOS: Natural sciences > Biological sciences

Other information

Authenticus ID: P-00A-1SX

DOI: 10.1002/bio.2639

Abstract (EN): 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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7