Gel permeantion chromatography can be used to separate which of the following:
(1) Lanthanides
(2) Alkaline earths
(3) Fatty acids
(4) Low molecular weight peptides
The correct answer is
(a)A and B
(b)B and C
(c)C and D
(d)A and D
Answer
Answer: C ✓ checked by 4AB · confidence high
The source book printed D; on checking, C is correct — see the explanation.
Stored key D ('A and D') confused statement D with option letter d. GPC (size exclusion) separates by molecular size: fatty acids (C) and low-MW peptides (D) are separable; lanthanide and alkaline-earth ions are not (ion exchange). Correct option (c) 'C and D', which is also the printed book key.
Explanation
The items are numbered (1)–(4) in the question but the options refer to them as A–D: A = lanthanides, B = alkaline earths, C = fatty acids, D = low-molecular-weight peptides. Gel permeation (size-exclusion) chromatography separates molecules according to their size as they permeate a porous gel. Organic molecules of differing size, such as fatty acids and low-molecular-weight peptides, can be separated this way. Lanthanide and alkaline-earth ions are small hydrated ions of almost the same size; they are separated by ion-exchange chromatography, not by GPC. Correct: C and D — option (c).