GC–ECD Method for Determination of Glucosidically Bound Aroma Precursors in Fresh Tea Leaves

Abstract

The possibility of using GC-ECD to determine glucosidically bound aroma precursors was investigated. Five b-D-glucopyranosides were derivatized with N-methylbis(trifluoroacetamide) (MBTFA) and then determined by GC-ECD, which showed these mono-glycosides (glucosides) could be separated and identified by GC. Repeatability, sensitivity and stability were tested, relative standard deviation (RSD) was in the range of 0.55-5.9%, the limit of detection (LOD) was lower than 10 -3 lg mL -1 , and the standard mixture was stable within 3 days (stored at 4°C, peak areas RSD \ 3%). Application of the developed derivatization and determination method to the fresh tea leaves showed that the glucosides could be accurately quantified (using phenyl b-D-glucopyranoside as internal standard). Because of its high sensitivity, the developed method was suitable for the determination of glucosides in fresh tea leaves.

Characteristic Fluctuations in Glycosidically Bound Volatiles during Tea Processing and Identification of Their Unstable Derivatives

“…A recently developed LC-MS method enabled us to simultaneously characterize and quantitate 10 glycosides in tea samples within 85 min after a simple pretreatment (Figure S1). The detection limit was 2.6–34.6 pmol/injection, which is comparable to the GC-MS methodology for TMS/TFA derivatives of GBVs . To our knowledge, this is the first report of the characterization and quantitation of GBVs in tea leaves based on LC-MS analysis.…”

“…The detection limit was 2.6− 34.6 pmol/injection, which is comparable to the GC-MS methodology for TMS/TFA derivatives of GBVs. 32 To our knowledge, this is the first report of the characterization and quantitation of GBVs in tea leaves based on LC-MS analysis. This study provides a precise and reliable method employing a simple pretreatment for GBV analysis, instead of hydrolysis or the use of glycoside derivatives currently required for GC or GC-MS. GBVs in Green Tea Leaves May Help To Screen for Suitable Tea Varieties for Black Tea Production.…”

Estimating the aroma glycosides in flue‐cured tobacco by solid‐phase extraction and gas chromatography–mass spectrometry: changes in the bound aroma profile during leaf maturity

“…Rearrangement of the aglycones may occur during the acidic hydrolysis and the activity of β‐ d ‐glycosidase was affected by the aglycone moiety for enzymatic hydrolysis. A direct analytical method of glycosidic extraction by GC–MS after trifluoroacetylation (TFA) derivatization has also been reported, with positive results.…”