Jump to main content
Jump to site search

Issue 43, 2017
Previous Article Next Article

Separation and detection of free D- and L-amino acids in tea by off-line two-dimensional liquid chromatography

Author affiliations

Abstract

D-amino acids are currently paid attention to as new physiologically active substances. Foodstuffs and beverages containing D-amino acids are a matter of interest. Until now, the profiles of D-amino acids have not been reported in natural and fermented teas except theanine. In this study, an off-line 2D-HPLC method combining a Gemini C18 column and a CHIRALPAK® IC-3 column or a self-prepared poly(MQD-co-HEMA-co-EDMA) monolithic capillary column was employed for the separation and detection of D-amino acids in tea samples with the co-existence of a large amount of L-amino acids. The free amino acid fractions in longjing, black, oolong, and pu-erh tea samples were separated and collected after pre-column derivatization using 9-fluorenylmethoxycarbonyl (FMOC) chloride in the reversed-phase mode, and then were concentrated and separated to D- and L-forms on a chiral column. Among them, the D-form of isoleucine (Ile) (1.0–1.6%), alanine (Ala) (0.1–0.8%), phenylalanine (Phe) (0.1–0.4%), valine (Val) (0.2–0.3%), serine (Ser) (0.1–0.2%), aspartic acid (Asp) (0.2%), and proline (Pro) (0.1%) were detected in longjing and oolong teas. Differences between natural tea and fermented tea in the profiles of D-amino acids as well as the total amino acids were also observed. The results provided useful information for the bio-function research of D-amino acids in tea.

Graphical abstract: Separation and detection of free d- and l-amino acids in tea by off-line two-dimensional liquid chromatography

Back to tab navigation

Supplementary files

Publication details

The article was received on 26 Jun 2017, accepted on 02 Oct 2017 and first published on 03 Oct 2017


Article type: Paper
DOI: 10.1039/C7AY01569K
Citation: Anal. Methods, 2017,9, 6131-6138
  •   Request permissions

    Separation and detection of free D- and L-amino acids in tea by off-line two-dimensional liquid chromatography

    X. Wang, H. Wu, R. Luo, D. Xia, Z. Jiang and H. Han, Anal. Methods, 2017, 9, 6131
    DOI: 10.1039/C7AY01569K

Search articles by author

Spotlight

Advertisements