2.6 Column chromatography
CCC fractions with highest purities of γ-T1 according to GC/MS analysis (generally CCC fractions 16-19, partly also CCC fractions 15 and 20 and scarcely CCC fractions 14 and 21) were further purified by column chromatography (1 cm inner diameter glass column filled with 5 g silica gel 60, deactivated with 20% water) according to Hammann et al. (2015). The selection criterion was a maximum of 5% interfering β-/γ-tocochromanols in relation to γ-T1 in the fraction. Selected CCC fractions were transferred to the column using a Pasteur pipette. For this purpose, the complete solution from the 2 mL brown glass GC vial (section 2.4) was individually placed onto the column and the vial was rinsed three more times with 0.5 mL of n -hexane. Silica fraction 1 (30 mL n -hexane) and silica fraction 2 (40 mLn -hexane/ethyl acetate, 99:1, v/v ) were collected in 100 mL pear shaped flasks. Based on initial trials, the subsequent silica fraction 3 (n -hexane/ethyl acetate, 95:5, v/v ) was subdivided into six aliquots of different volume, namely fraction 3.1 (0-15 mL), fraction 3.2 (15-17 mL), fraction 3.3 (17-20 mL), fraction 3.4 (20-22 mL), fraction 3.5 (22-25 mL) and fraction 3.6 (25-50 mL). Fractions 3.1 to 3.5 were collected in 20 mL brown glass derivatisation tubes and fraction 3.6 in a 100 mL brown glass pear shaped flask. Finally, more polar compounds were eluted with 40 mL ethyl acetate (silica fraction 4) into a 100 mL pear shaped flask. Fractions 1, 2 and 4 were evaporated to dryness in a rotary evaporator and fractions 3.1-3.6 by means of a gentle stream of nitrogen. Residues of all fractions were taken up with n -hexane and transferred into 2 mL brown glass GC vials, respectively. Aliquots were trimethylsilylated and measured by GC/MS (section 2.5).