Exp 5.4: Carbohydrates (TLC) Flashcards
purpose of TLC
to separate products in the acid (glucose) and enzymatic (glucose, maltose, dextrin) hydrolysates of starch and glycogen
polarity of the stationary phase
(phase of silica gel)
normal phase
stationary phase used
silica gel
mobile phase used
solvent systems
which is more polar: silica gel or solvent systems
silica gel
silica gel used
normal phase siliga gel G
meaning of G in normal phase silica gel G
gypsum (CaSO4)
what is present on the surface of normal phase silica gel G
-OH groups
physical interactions involved
hydrogen bonding or dipole-dipole (polar) interaction
direction of solvent front
ascending
principle involved in separation based on physical states of the stationary and mobile phases
adsorption
separation of the carbohydrates in the hydrolysate will depend on their ________
polarity
solvent system:
reagents and ratio
acetonitrile: water
(85:15)
concentration of EDTA and sulfuric acid used
0.3% 1-naphthyl EDTA and 5% sulfuric acid in MetOH
visualizing agent
p-anisaldehyde
color of spots when visualizing agent (p-anisaldehyde) is used
blue/ blue-green/ green
basis of visualizing agent (p-anisaldehyde)
based on complex with the sugar
T/F:
the less -OH groups, the more polar the sugar is more adsorbed on normal phase silica gel
false
more -OH groups = more polar
Arrange from most polar to least:
maltose, dextrin, glucose
glucose > maltose> dextrin
