Dynamic calibration approach for determining catechins and gallic acid in green tea using LC-ESI/MS

Catechins and gallic acid are antioxidant constituents of Camellia sinensis, or green tea. Liquid chromatography with both ultraviolet (UV) absorbance and electrospray ionization mass spectrometric (ESI/MS) detection was used to determine catechins and gallic acid in three green tea matrix materials that are commonly used as dietary supplements. The results from both detection modes were evaluated with 14 quantitation models, all of which were based on the analyte response relative to an internal standard. Half of the models were static, where quantitation was achieved with calibration factors that were constant over an analysis set. The other half were dynamic, with calibration factors calculated from interpolated response factor data at each time a sample was injected to correct for potential variations in analyte response over time. For all analytes, the relatively nonselective UV responses were found to be very stable over time and independent of the calibrant concentration; comparable results with low variability were obtained regardless of the quantitation model used. Conversely, the highly selective MS responses were found to vary both with time and as a function of the calibrant concentration. A dynamic quantitation model based on polynomial data-fitting was used to reduce the variability in the quantitative results using the MS data.

Medienart:

E-Artikel

Erscheinungsjahr:

2011

Erschienen:

2011

Enthalten in:

Zur Gesamtaufnahme - volume:83

Enthalten in:

Analytical chemistry - 83(2011), 16 vom: 15. Aug., Seite 6169-76

Sprache:

Englisch

Beteiligte Personen:

Bedner, Mary [VerfasserIn]
Duewer, David L [VerfasserIn]

Links:

Volltext

Themen:

632XD903SP
8R1V1STN48
Antioxidants
Biological Products
Catechin
Gallic Acid
Hydrolyzable Tannins
Journal Article

Anmerkungen:

Date Completed 06.12.2011

Date Revised 21.11.2013

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1021/ac200372d

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM210161175