Separation of fructopyranose ,fructofuranose

[Chandresh K. Soni]

Can anybody help me on the separation of fructopyranose in fructofuranose. Want to analyze the fructofuranose and want to determine the content of fructopyranoze in Fructose.
these compounds are interconvertable in each other. is it possible to analyze on HPLC with chiral column using ELSD Detector.

If Yes then please help me. if these are not analyzable by HPLC then please suggest me the suitable Method of Analysis of these compounds in each other.
I also have the USP Method of D-Fructose but it gives only assay of D-Fructose.
please help me.

[tom jupille]

I would guess those are separable on one of the cation exchange columns in the Ca++, PB++, or Ag+ form, at low temperature. I know from experience that alpha and beta d-glucose are separable on the Ca++ form column at sub-ambient temp. The eluent is plain water, so ELSD should work fine.

Check with BioRad or Dionex for appropriate columns.

[mardexis]

As Tom suggested I think it should be fairly easy to separate the 5 membered ring furanose from the six membered pyranose. Not sure why you would want to though. If you dissolve the sample in water it should convert to 70% pyr and 22% fur with three other smaller forms. These are equilibrium values and not really useful for characterizing your samples (I think?) People generally run these assays at high temperature so that they interconvert rapidly and the peaks will merge into one easily quantified peak of fructose by HPLC.