Chromatography Forum

Hi all!

Is it normal that PDA-spectra for compounds when working in normal phase are worst than the ones in reversed phase HPLC?

Is identification of compounds from their spectra still reliable in RP-HPLC?

I noticed that there are some changes between spectra maximums from RP to NP-HPLC (I work with tocopherols & tocotrienols)

thank you in advance

I don't know what you mean by "worse".

There is no reason to expect exactly the same spectrum in vastly different chemical environments (aqueous vs. non-aqueous), especially if the chromophores are coupled to ionizable groups.

UV spectra are generally are "information poor". I would not rely on UV spectra for positive identification under any circumstances.