Nucleosil 100 5 c18 ec 125 4 column

Betulin quantification was performed using an LC-20A prominence HPLC system (Shimadzu, Kyoto, Germany). The mobile phase, a mixture of acetonitrile and water with the addition of 0.1% (v/v) phosphoric acid, was used as a gradient system for chromatographic separation. For efficient separation, gradient conditions were used according to the isocratic/gradient modes developed by Armbruster et al. [40 (link)]. A Nucleosil 100-5 C18 EC 125/4 column with a precolumn Universal RP EC 4/3 (Macherey-Nagel, Düren, Germany) was kept at 40 °C and a flow rate of 1.2 mL/min was used. A sample volume of 100 µL was injected and the peaks were detected at 210 nm. The retention time of betulin was approximately 7.5 min.

The LC-20A prominence HPLC system (Shimadzu, Kyoto, Japan) was used for betulin analysis. The mobile phase was composed of acetonitrile and water with the addition of 0.1% (v/v) phosphoric acid. For efficient betulin quantification, gradient conditions were used according to the isocratic/gradient modes developed by Armbruster et al. [59 (link)]. The flow rate was set to 1.2 mL/min, the injection volume was 100 µL and the oven temperature was 40 °C. For HPLC separation, a Nucleosil 100-5 C18 EC 125/4 column together with a precolumn Universal RP EC 4/3 (Macherey-Nagel, Düren, Germany) was used. The retention time of betulin was approximately 7.5 min and the detection wavelength was set at 210 nm.