... powderSpecification: ST-1 Rebaudioside A 80%, 95%, 97%, 99% HPLC JECFA ST-2 Rebaudioside A 60% / Steviol Glycosides 90 ... %, 95% HPLC JECFA ST-3 Stevioside 85%, 90%, 95% HPLC JECFA ST-4 Steviol Glycosides 85 ... %, 90%, 95% HPLC JECFA Structural Formula: Description:1 ... auxiliary method. Extraction Stevia herb / Stevioside HPLC