Isolation of squalene
A column was prepared with 210 g of silica gel and hexane. Silflower oil (7.0 g) was loaded into the column and eluted with a gradient solvent from 0 to 2% (v/v) ethyl acetate in hexane. Squalene was eluted before triglycerides. The solvent was removed by a rotary evaporator and then a vacuum pump, and squalene was weighed to obtain the yield. Isolation of squalene was conducted in duplicate. The molecular structure was confirmed with 1H NMR.