Caffeine, catechins, EGCG, L-theanine and total polyphenols in tea and related materials.
| Tests | Caffeine, catechins, EGCG, L-theanine, total polyphenols as catechins |
|---|---|
| Method | HPLC or UPLC; total polyphenols by Folin-Ciocalteu UV/Vis |
| Results | Reported against your specification or label claim, with pass/fail where limits apply. |
| Price | Quoted per project |
The chromatographic tests separate the named compounds and measure them against reference standards. The total polyphenols test is a colorimetric estimate, described in its section.
Green tea specifications state polyphenols, catechins and caffeine on a named basis, so tell us yours.
Measures caffeine by HPLC against a reference standard, for tea, coffee and other caffeine-containing materials and products.
Measures caffeine by UPLC, a higher-pressure form of liquid chromatography. It is listed separately from the HPLC caffeine test as a separate catalog entry; both report caffeine.
Measures green tea catechins and caffeine together by UPLC. The USP Powdered Decaffeinated Green Tea Extract monograph describes that extract as prepared from young unfermented leaves and leaf buds of Camellia sinensis and sets requirements for its polyphenols, (-)-epigallocatechin-3-O-gallate and caffeine. Tell us which catechins your specification names.
Measures (-)-epigallocatechin-3-O-gallate (EGCG), the catechin the USP Powdered Decaffeinated Green Tea Extract monograph uses as the reference compound for its polyphenols, by UPLC as a single compound.
Measures L-theanine, an amino acid found in tea, by HPLC. Tell us whether your specification also addresses the D-form.
A colorimetric estimate of total polyphenols using the Folin-Ciocalteu reagent, expressed as catechins. The reagent reacts with phenolic compounds and with other reducing substances such as ascorbic acid, so the result is not specific to catechins and does not identify individual compounds. The USP Powdered Decaffeinated Green Tea Extract monograph expresses its polyphenols as EGCG; tell us which basis your specification uses.
Send the material sealed, labeled and protected from light.
Tell us the material, the plant part or extract, and the specification or label claim. We confirm the sample amount at quote.
Questions about a sample or a method, call 360-967-7010 or email [email protected].
