Figure 8From: Evaluation and differentiation of the Betulaceae birch bark species and their bioactive triterpene content using analytical FT-vibrational spectroscopy and GC-MSThe chromatogram and mass spectrum of betulin (ethanol/methanol, elution time 23.7 min). Tcol:50 °C(1 min)20 °C/min l;a 310 °C(15 min); M=442.Back to article page