Chromatography Forum

I met with the sythesized sample ,there are about 4-5 isomers among the mixture which is very hard to dissolve ,and even though I run very low slope gradient ,the 4-5 compounds are very close ,futhermore the peak width is very large each !every compound is very basic ,and the MW is not very large !how should I do futher on the mobile phase and packing material ,we can pack column ourseves !many thanks !

How large are the peaks?
If they're huge, making a more dilute preparation will help with respect to solubility and resolution.

What sort of solvents have you tried?
Are the isomers positional or optical?
Can you give more information as to the nature of the compounds.

Or: How do you control the pH? What buffer are you using? Details of the gradient? Injection solvent? ....................