According to Japanese Pharmaceutical Excipients 2018*, “Purity test" for “Purified Stevia Extract" should be carried out with a column filled with octadecylsilylated silica gel. The Silica C18M 4E confirmed the requirements were met.

System suitability requirementsElution order (Solution for system performance): 4-tert-butyl benzoic acid, steviol
Resolution between 4-tert-butyl benzoic acid and steviol (Solution for system performance): ≥ 6
Relative standard deviation (RSD) of the peak area of steviol (Standard solution): ≤ 1.5% (repeated 6 times)

*The version at the time of the application acquisition.

Sample: 20 µL
(Solution for system performance) 0.01 mg/mL of 4-tert-Butyl benzoic acid and 0.05 mg/mL of Steviol in 50 % CH₃OH

1. 1.4-tert-Butyl benzoic acid 0.01 mg/mL
2. 2.Steviol 0.05 mg/mL