MSTFA-derivatised oligosaccharides

[lmh]

We do GC analysis of MOX/MSTFA derivatised sugars, and get on fine with sucrose etc., but we're struggling with stachyose (tetrasaccharide) and verbascose (pentasaccharide). Are they just too big? At one stage they seemed to work, coming off a ZB-5HT column at fairly high temperatures, but recently we've been failing completely, and we don't know if it's a problem with chromatography or derivatisation. I'd be grateful if anyone's able to share any experiences?

[carlo.annaratone]

that stuff cannot come out of a standard capillary column. the heaviest I've ever seen is some tri saccharide. Maybe with high temp columns you could do it, but i would say that GC is not really the correct tool for the job

[MSCHemist]

They sell HT GC stuff. You probably need a high temperature column and some thermostable inlet consumables.

[MSCHemist]

I tried silyation of nucleotides, inosinate monophosphate and guanylate monophosphate and never saw anything other than reaction componenets and silylated impurities. I finally gave up and am looking to aquire a used capilary electrophoresis.