Theanine is a kind of amino acid contained in tea and has mainly anti-stress and relaxation effects. The analysis of theanine in commercially available supplements was performed in HILIC mode using Asahipak NH2P-50 4E. A calibration curve with high linearity was obtained in the concentration range of 0.001 to 1 mg/mL, and the recovery rate was confirmed to be good at approximately 90 %.
(Pretreatment for sample solution of commercial supplement)
(1) Add 5 mL eluent to 5 mg sample and sonicate for 10 minutes
(2) Filtrate the supernatant with a 0.45 μm filter
Sample : 20 μL
Standard
1. Theanine 0.1 mg/mL
(in eluent)
Column : Shodex Asahipak NH2P-50 4E (4.6 mm I.D. x 250 mm) Eluent : 20 mM NaH2PO4 + 30 mM H3PO4 aq./CH3CN=25/75 Flow rate : 1.0 mL/min Detector : UV (210 nm) Column temp. : 30 °C
Sample Name Index
Operation Manual / Certificate of Analysis
Operation Manuals and Certificate of Analysis / Inspection Certificate for the following products can be downloaded here.
Product Name Index
Applications
- Amino Acids (2) (NN-814)
- Amino Acids (3) (P-421S)
- Amino Acids (4) (YS-50)
- Amino Acids (5) (YS-50)
- Histidine and 1-Methylhistidine
- Separation of Carcinogenic Tryptophan Pyrolysis Products (ES-502C 7C)
- LC/MS Analysis of Essential Amino Acids (NH2P-40 2D)
- LC/MS Analysis of Citrulline (NH2P-40 2D)
- LC/MS Analysis of GABA (NH2P-40 2D)
- LC/MS Analysis of Tranexamic Acid (NH2P-40 2D)
- Simultaneous Analysis of Saccharides, Organic Acids and Amino Acids with LC/MS (VG-50 2D)
- Simultaneous Analysis of Hydrophilic Substances in Energy Drink with LC/MS (VG-50 2D)
- Simultaneous Analysis of Amino Acids with LC/MS (VC-50 2D)
- Analysis of Theanine (NH2P-50 4E)
- Analysis of GABA in a Supplement (NH2P-50 4E)
- Effects of Organic Solvent Concentration on HILIC Mode (NH2P-50 4B)