Question

Expert Q&A Done TLC plate w silica gel in order of 1 cholesterol(standard) 2. Lecithin (standard) 3. Triglyceides (standard) 4. Egg(food sample) 5. Milk ( food sample) 1. Which lipids are in your food extracts? 2.Which lipids seems to be most abundant? Which is least abundant? 3.Do other lipids appear to be in food extracts besides the standards? 4. Explain the relative migration of the three standards from their structures and the relative polarities of the solvent mixture and the silica gel.

Answer 1

1) both the food extracts have lecithin and triglycerides.

2) lecithin is most abundant as a big blotch is observed at its location and least is cholesterol as there is not blotch whatsoever at it corresponding location.

3)yes . There are 2 blotches (bands) - one at an intermediate location and one at the top which donor correspond to any of the standard lipid tlc profiles.

4) the more hydrophobic the lipid is the longer it will stay in the mobile phase (solvent mixture) and the higher it's band shall be on the tlc plate. Cholesterol is the most hydrophobic among them with lots of ring structures followed by triglycerides which have intermediate polarity due to the -OH groups and lecithin is the most polar (charged one) as it is a phospholipid.