... Tea Extract Powder Specification:Polyphenols 20%-98% EGCG 10%-95%,Catechins 10%-90% Excellent quality ... %, 60%, 65%, 70%, 75%, 80%, 90% HPLC 3. EGCG 10%, 15%, 20%, 30%, 35%, 40%, 45%, 50%, 55 ... combinations for Polyphenols, Catechins, EGCG, Caffeine. For example, Polyphenols 95%+Catechins 70%+EGCG 40%+Caffeine 5% Specification Sheet ... UV> 95.0%Catechins by HPLC> 70.0%EGCG by HPLC> 40.0%Caffeine by HPLC< 5. ...