TLC

Question 1

How it separates chemicals

Answer 1

• Uses a solid stationary phase –> separation is due to adsorption onto the surface of the solid and form a spot

Question 2

Identification

Answer 2

• To identify an amino acid/compound:

o Calculate retardation factor
o Compare retardation factor to known retardation factors of know aa.

• Some substances will not separate because compounds have similar retardation value and will show up as one large spot.

Question 3

Q Describe how TLC can be used to show that an impure solid contains multiple compounds?

Answer 3

• Dissolve in ethanol (solvent)
• Draw a period line on the TLC
• Place spot of dissolved salt on the period line
• Add spots of pure compound (A+B)
• Place in a beaker with a solvent- seal
• Allow solvent to rise
• Use UV light to identify the spot- Calculate RF or compare to pure samples.
• Use controls alongside to compare

Question 4

Doing TLC with second orientation

Answer 4

unlikely that two compounds have the same retardation factor with two different solvents.