▒ Content
L-Theanine, when calculated on the dried basis, contains 98.0－102.0%
of L-theanine (C7H14N2O3).

▒ Description
L-Theanine occurs as a white crystalline powder. It is odorless and has a slightly characteristic and sweet taste.

▒ Identification
(1) To 5 ml of L-Theanine solution (1 → 1,000), add 1 ml of
ninhydrin solution (1 → 1,000), and heat for 3 minutes. A purple color develops.
(2) Dissolve about 1 g of L-Theanine in 10 ml of diluted hydrochloric acid (1 → 2), heat with a reflux condenser on a water bath for 6 hours, and add water to make 20 ml.
Transfer 5 ml of this solution into a test tube, and add 2 g of sodium hydroxide.
Suspend a red litmus paper moistened with water in the test tube, cover the mouth of
the test tube, and heat in a water bath for 5 minutes. The color of the litmus paper changes to blue.

▒ Purity
(1) Specific rotation [ ]20
D α : +7.7 － +8.5 (2.5 g, water, 50 ml, on the dried basis).
(2) Clarity and color of solution colorless, almost clear (1.0 g, water 20 ml).
(3) pH 5.0－6.0 (1.0 g, water 100 ml).
(4) Chloride Not more than 0.021% as Cl (0.5 g, Control solution 0.01 mol/l hydrochloric acid 0.30 ml).
(5) Heavy metals Not more than 10 μg/g as Pb(2.0 g, Method 1, Control solution Lead Standard Solution 2.0 ml).
(6) Arsenic Not more than 4.0 μg/g as As2O3 (0.50 g, Method 1, Apparatus B).
Loss on Drying Not more than 0.5% (105℃, 3 hours).
Residue on Ignition Not more than 0.20%.
Assay Weigh accurately about 0.35 g of L-Theanine, and proceed as directed under the Assay in DL-Alanine.
1 ml of 0.1 mol/l perchloric acid = 17.420 mg of C7H14N2O3

▒ Product : L-Theanine (Manufacture : THEANINEKOREA Inc.)
ⅰ) Assay : >99% up
ⅱ) Specific rotation(20℃) : +7.7° ~ +8.2°
- Packing : 500g, 1kg, 10kg