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Journal of Analytical Methods in Chemistry
Volume 2015, Article ID 280167, 7 pages
http://dx.doi.org/10.1155/2015/280167
Research Article

Optimization of a CUPRAC-Based HPLC Postcolumn Assay and Its Applications for Ginkgo biloba L. Extracts

1Department of Analytical and Toxicological Chemistry, Faculty of Pharmacy, Medical Academy of Lithuanian University of Health Sciences, Eiveniu Street 4, LT-50161 Kaunas, Lithuania
2Department of Pharmacognosy, Faculty of Pharmacy, Medical Academy of Lithuanian University of Health Sciences, Eiveniu Street 4, LT-50161 Kaunas, Lithuania

Received 19 May 2015; Accepted 21 June 2015

Academic Editor: Hassan Y. Aboul Enein

Copyright © 2015 Laura Rimkiene et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The aim of the present work was to improve and validate the HPLC-CUPRAC postcolumn method for the evaluation of active antioxidant markers from the acetonic extracts of Ginkgo biloba leaves. Improvement of the HPLC online assay was performed by evaluating the suitable loop temperature, the reaction loop length, and the impact of flow rate. Separation of the analytes was performed by the HPLC method on an ACE C18 analytical column using a gradient elution program. The separated antioxidant markers in the extracts reacted with copper(II)-neocuproine (Cu(II)-Nc) reagent in the postcolumn reaction coil. The reagent was reduced by antioxidants to the copper(I)-neocuproine (Cu(I)-Nc) chelate with a maximum absorption at 450 nm. Validation experiments confirmed sufficient precision, sensitivity, and effectiveness of the corresponding method, which could be used for further evaluations of active antioxidant compounds in similar plant materials.