RPLC: polymeric VS monomeric and C18 VS C30

[yhan]

Hello, nice to meet u all! I'm new here and so lucky i found this forum! ^_^

First of all, i'm a biology student and now i'm doin a project about carotenes and its analysis by RPLC. So my question is wat is difference between polymeric and monomeric stationary phase? and why polymeric can give better resolution? Besides, why C30 is better than C18 in carotene analsyis by RPLC? Is it because the hydrophobic and moieties of their alkyl length? Thanks and sorry for the inconvenence!

[Uwe Neue]

Since you are doing a project, I suggest to read all papers by Lane Sander in Anal. Chem and J. Chromatogr.

[adam]

If I'm not mistaken, one of the unique aspects of C30 columns is that they separate by shape selectivity. So for molecules that have very similar molecular weight and polarity, but have a slightly different geometric shape, the C30 may work better than other alternatives would.