GABA (γ-aminobutyric acid) is a functional ingredient in foods and has blood pressure suppressing and relaxing effects. It is one of the compounds registered as the Japanese functional ingredient in many numbers. In this application, a commercial supplement containing GABA was analyzed by a polymer-based amino column, Asahipak NH2P-50 4E, under HILIC mode. Supplements, which do not contain many interfering matrices can be analyzed without using a post-column method. It provided a good linear calibration curve in the concentration range 1 to 1,000 mg/L.
1) Take out the content (powder) from a commercial GABA supplement hard capsule
2) Dissolve 5 mg of the removed powder in 25 mL of eluent.
3) Filter using a 0.45-µm membrane filter and use it as the injection sample.
Sample : 5 μL
GABA (γ-Aminobutyric acid) 1000 mg/L
Column : Shodex Asahipak NH2P-50 4D (4.6 mm I.D. x 250 mm) Eluent : 20 mM Sodium phosphate buffer (pH7.0)/CH3CN=30/70 Flow rate : 1.0 mL/min Detector : UV (210 nm) Column temp. : 30 °C