neutral sugar-GC or HPLC

[pchanida]

I analysed monosaccharide composition in polysaccharide sample by GC using methanolysis and TMS derivatisation. There's no fucose found. But when I analysed by HPLC (ion exchange) using TFA hydrolysis and cyanoacetamide derivatisation. Fucose peak was found. May be I do something wrong?

[Peggsy]

Have i got this right, you hydrolysed the sample for HPLC with TFA but there was no hydrolytic step prior to methanolysis and silylation for the GC sample?

Greg

[Consumer Products Guy]

If I was only looking for monosaccharides in my lab, I would dissolve and use TMS derivatization. No methanolysis. HPLC with refractive index detector (no derivatization) can also work.

Are you trying to do total monosaccharides or need to quantitate different monosaccharides, I guess that's the real question.