According to Japanese Pharmaceutical Excipients 2018 method, steviol purity test of purified stevia extracts should be used the HPLC column packed with octadecylsilylated silica gel. The system suitability requires to satisfy resolution between steviol and the internal standard 4-tert-butyl benzoic acid, to be ≥ 6.0. Also, the relative standard deviation of steviol to be ≤ 1.5 % for the six repeated analysis. It was confirmed that Silica C18M 4E satisfies all required conditions.




















Sample : 20 μL
1. 4-tert-butyl benzoic acid 0.01 mg/mL
2. Steviol 0.05 mg/mL

Column       : Shodex Silica C18M 4E (4.6 mm I.D. x 250 mm)
Eluent       : 0.085 % H3PO4/CH3CN=9/11
Flow rate    : 1.0 mL/min
Detector     : UV (213 nm)
Column temp. : 40 °C