Orthogonal Analytical Methods for Botanical Standardization: Determination of Green Tea Catechins by qNMR and LC-MS/MS
journal contributionposted on 2013-12-22, 00:00 authored by José G. Napolitano, Tanja Gödecke, David C. Lankin, Birgit U. Jaki, James B. McAlpine, Shao-Nong Chen, Guido F. Pauli
The development of analytical methods for parallel characterization of multiple phytoconstituents is essential to advance the quality control of herbal products. While chemical standardization is commonly carried out by targeted analysis using gas or liquid chromatography-based methods, more universal approaches based on quantitative 1H NMR (qHNMR) measurements are being used increasingly in the multi-targeted assessment of these complex mixtures. The present study describes the development of a 1D qHNMR-based method for simultaneous identification and quantification of green tea constituents. This approach utilizes computer-assisted 1H iterative Full Spin Analysis (HiFSA) and enables rapid profiling of seven catechins in commercial green tea products. The qHNMR results were cross-validated against quantitative profiles obtained with an orthogonal LC-MS/MS method. The relative strengths and weaknesses of both approaches are discussed, with special emphasis on the role of identical reference standards in qualitative and quantitative analyses.
The present work was financially supported by the National Institutes of Health (NIH) through grant RC2 AT005899, awarded to Dr. Guido F. Pauli by the National Center for Complementary and Alternative Medicine (NCCAM). Dr. José G. Napolitano was supported by the United States Pharmacopeial Convention as part of the 2012/2013 USP Global Research Fellowship Program. The purchase of the 900-MHz NMR spectrometer and the construction of the CSB were funded by the NIH grant P41 GM068944, awarded to Dr. Peter G.W. Gettins by the National Institute of General Medical Sciences (NIGMS).
Publisher StatementNOTICE: This is the author’s version of a work that was accepted for publication in Journal of Pharmaceutical and Biomedical Analysis. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Pharmaceutical and Biomedical Analysis, 2013 DOI: 10.1016/j.jpba.2013.06.017