[Swelmer]

Dear all,

Im having a really hard time figuring out what mobile phase is suitable for separating glucose, fructose and sucrose. (I'm running a synthesis of hydroxymethylfurfural from sucrose). However, as for now I'm unable to separate my sugars hence i cannot tell if sucrose is hydrolysed.
Im using "normal" silica coated TLC plates and im looking for a suitable method of approach so as to obtain a sample that gives 3 spots (for each sugar)
Im hoping anyone of you might be able to help me out
Kind regards A mean' o' acid

[Babcock_Hall]

Chapter 10 in Egon Stahl's book on Thin Layer Chromatography covers carbohydrates, and shows separation among various monosaccharides and disaccharides.  You will probably want to use a a buffered solution to impregnate the TLC plate; among the substances used are acetate and borate.  IIUC Borate can form complexes with diols.

[Swelmer]

i cannot access that book, it is not in the school library and its a little much to buy for just a separation method on carbohydrates

[Babcock_Hall]

You can try Stahl and Kaltenbach Journal of Chromatography 5, 351, 1961.  That is one of the references at the end of the chapter.  But if you do a good deal of thin-layer chromatography, a used copy of the second edition is a handy thing to have.
EDT
You might be able to obtain the book through interlibrary loan.

[MOTOBALL]

A quick Google search (TLC monosaccharides) finds,

Separation and detection of sugars and alditols on thin layer chromatograms,
Nam Soo Han & JF Robyt, Carbohydrate Res. 313 (1998) 135-137.

It gives thepaper in full, very short note all details you need

NOTE the use of multiple "ascents" i.e. repeated "runnings" of the same plate to achieve the separations !!!
You may have to run more than twice....
Very easy chromatography and detection systems
 
The sucrose should have lower Rf than glucose/fructose pair.
I would spot something like as follows,

Plate A    Glu std    Sample   Glu std   Sample  Glu Std 
Plate B    Fru std     sample   fru std    sample  fru std
Plate C    Glu std    sample    fru std   sample   glu std
Plate D    mixed Glu/Fru std    sample    mixed glu/Fru std  sample  mixed glu/fru std

Beware of edge effects !!!

Good Luck,
Motoball

[Babcock_Hall]

JF Robyt and BJ White's textbook Biochemical Techniques has a nice section on the TLC of carbohydrates on pp. 107-108.  I see glucose mentioned, but I don't see fructose or sucrose.

[MOTOBALL]

I should have mentioned that this paper does not explicitly give details for fructose; however, it does provide a very good starting point.

Good TLC technique is essential for achieving resolution of difficult pairs. In case you have not done much TLC,

1. Do not overload the sample; keep spot as small as possible; make sure spot is DRY before running the plate

2. Air space above mobile phase should be saturated with vapours of mobile phase; this best achieved by lining the tank/jar with filter paper and allowing to stand for about an hour.

3. Do not let the sides of the plate touch the filter paper.

4. Air-dry the plate well between runs !!

Please let us know if it works for your analysis.

Motoball

P.S. If you use the Han/Robyt method note that you MUST measure separately the MeCN/EtOAc/PrOH/H2O volumes, and then mix.