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Determination of theanine and gamma-aminobutyric acid in tea by high performance- liquid chromatography with precolumn derivatization.
Se Pu. 2012 Feb; 30(2):184-9.SP

Abstract

A method of precolumn derivatization-high performance liquid chromatography (HPLC) for the determination of theanine and gamma-aminobutyric acid (GABA) in tea was established. o-Phthalaldehyde (OPA) and N-acetyl-L-cysteine (NAC) were chosen as the derivatization reagents. The effects of teapolyphenol (Tp), proline (Pro) and Vitamin C (Vc) on derivatization yields were investigated. The results indicated that Vc not only stabilized the stock solution of OPA, but also enhanced the yield of GABA derivative. However, the yield of theanine derivative was less affected. The HPLC separation system was also optimized. The resolution of the derivatives was improved by adjusting the pH value and phosphate-citric buffer concentration of the mobile phase. The limits of detection (LODs) for GABA and theanine were 3.01 x 10(-5) mmol/L and 7.98 x 10(-5) mmol/L, and the limits of quantification (LOQs) were 9.99 x 10(-5) mmol/L and 2.658 x 10(-4) mmol/L, respectively. The linear ranges of GABA and theanine were 0.01 - 0.4 mmol/L with the correlation coefficient of 0.996 and 0.05 - 0.8 mmol/L with the correlation coefficient of 0.995, respectively. The main recoveries for GABA and theanine in green tea, Oolong tea, and black tea, ranged from 99.29% to 119.60% and from 62.88% to 141.06% respectively. The method with simple procedure and efficient separation was proved to be suitable for the determination of GABA and theanine in tea.

Authors+Show Affiliations

Hangzhou Institute of Tea, All China Federation of Supply and Marketing Cooperatives, Hangzhou 310016, China. tyfaf@sohu.comNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

22679834

Citation

Tu, Yunfei, et al. "Determination of Theanine and Gamma-aminobutyric Acid in Tea By High Performance- Liquid Chromatography With Precolumn Derivatization." Se Pu = Chinese Journal of Chromatography, vol. 30, no. 2, 2012, pp. 184-9.
Tu Y, Yang X, Zhang S, et al. Determination of theanine and gamma-aminobutyric acid in tea by high performance- liquid chromatography with precolumn derivatization. Se Pu. 2012;30(2):184-9.
Tu, Y., Yang, X., Zhang, S., & Zhu, Y. (2012). Determination of theanine and gamma-aminobutyric acid in tea by high performance- liquid chromatography with precolumn derivatization. Se Pu = Chinese Journal of Chromatography, 30(2), 184-9.
Tu Y, et al. Determination of Theanine and Gamma-aminobutyric Acid in Tea By High Performance- Liquid Chromatography With Precolumn Derivatization. Se Pu. 2012;30(2):184-9. PubMed PMID: 22679834.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Determination of theanine and gamma-aminobutyric acid in tea by high performance- liquid chromatography with precolumn derivatization. AU - Tu,Yunfei, AU - Yang,Xiufang, AU - Zhang,Shikang, AU - Zhu,Yuejin, PY - 2012/6/12/entrez PY - 2012/6/12/pubmed PY - 2013/7/16/medline SP - 184 EP - 9 JF - Se pu = Chinese journal of chromatography JO - Se Pu VL - 30 IS - 2 N2 - A method of precolumn derivatization-high performance liquid chromatography (HPLC) for the determination of theanine and gamma-aminobutyric acid (GABA) in tea was established. o-Phthalaldehyde (OPA) and N-acetyl-L-cysteine (NAC) were chosen as the derivatization reagents. The effects of teapolyphenol (Tp), proline (Pro) and Vitamin C (Vc) on derivatization yields were investigated. The results indicated that Vc not only stabilized the stock solution of OPA, but also enhanced the yield of GABA derivative. However, the yield of theanine derivative was less affected. The HPLC separation system was also optimized. The resolution of the derivatives was improved by adjusting the pH value and phosphate-citric buffer concentration of the mobile phase. The limits of detection (LODs) for GABA and theanine were 3.01 x 10(-5) mmol/L and 7.98 x 10(-5) mmol/L, and the limits of quantification (LOQs) were 9.99 x 10(-5) mmol/L and 2.658 x 10(-4) mmol/L, respectively. The linear ranges of GABA and theanine were 0.01 - 0.4 mmol/L with the correlation coefficient of 0.996 and 0.05 - 0.8 mmol/L with the correlation coefficient of 0.995, respectively. The main recoveries for GABA and theanine in green tea, Oolong tea, and black tea, ranged from 99.29% to 119.60% and from 62.88% to 141.06% respectively. The method with simple procedure and efficient separation was proved to be suitable for the determination of GABA and theanine in tea. SN - 1000-8713 UR - https://www.unboundmedicine.com/medline/citation/22679834/Determination_of_theanine_and_gamma_aminobutyric_acid_in_tea_by_high_performance__liquid_chromatography_with_precolumn_derivatization_ DB - PRIME DP - Unbound Medicine ER -
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