Suggest a buffer and mobile phase composition to get the best separation given:
1. HPLC instrument
2. C18 reverse phase column
3. 1mM solution of each of the following compounds in Methanol
4. Mobile phase is methanol-buffer mixture
Compounds are 3 seperate groups:
1. Carboxylic Acids:
a. Benzoic acid
b. Phthalic acid
c. Toluic acid
3.Amino Carboylic Acids:
a. 4-aminobenzoic acid
b. 2-aminobenzoic acid
To answer this interesting question, I think you will need to remember how the chromatography process works. I think it is desirable to have the solute particles to have some time on the column and some time in the mobile phase.
Since you are using a reversed phase column, the mobile phase will be ...