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Existing Methods‐Compendium
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USP‐
Powdered Decaffeinated Green Tea Extract ‐2014
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ISO 14502
Determination of substances characteristic of
green and black tea‐2005
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Part 1: Content of total polyphenols in tea —Colorimetric method using
Folin‐Ciocalteu reagent
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Part 2: Content of catechins in green tea —Method using high‐
performance liquid chromatography
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GB/T8312 (China)
Tea‐Determination of caffeine content‐2002
Fitness for Purpose (proposal)
The method must be suitable for analysis of tea
catechins, caffeine and theaflavins in tea leaf, tea
extract, powdered tea extract, liquid tea and tea
extract in other herbal blend matrices.