Methods of quantifying saponins present in particles comprising saponin and lipid

A method of quantifying saponins present in particles comprising saponin and lipid, wherein the saponins of the particles comprise a triterpene core comprising a C26 methyl group comprising three protons, the method comprising steps of:

• (1) isolating the saponins from the lipids of the particles comprising saponin and lipid by reversed phase solid phase extraction of the saponins from a predetermined amount of the particles comprising saponin and lipid, thereby obtaining isolated saponins;
• (2) lyophilizing the isolated saponins, thereby obtaining lyophilized saponins;
• (3) preparing a solution of the lyophilized saponins and a predetermined amount of an internal standard compound that comprises one or more protons in deuterated methanol;
• (4) generating a quantitative proton NMR spectrum of the solution of the lyophilized saponins and the internal standard compound including a signal for the three protons of the C26 methyl group of the triterpene core of the saponins and a signal for the one or more protons of the internal standard compound;
• and
• (5) comparing the signal for the three protons of the C26 methyl group of the triterpene core of the saponins and the signal for the one or more protons of the internal standard compound.