Chromatography Forum

I wanted to do a TMS derivatization on a polysaccharide and was wondering whether a DB-225 column would work. I had originally gotten this column for aditol acetate derivatization but then started considering a TMS derivatization. Would you guys think it wise to go ahead with this? What do you guys recommend?

I think you "can", but here I would try a DB-1 or DB-5 type myself. And I'd likely use a specialty high-temperature column for a derivatized polysaccharide, as those TMS groups will add a lot of mass.

I use a db-5 column for paan (peracetylated aldonitrile) derivatives of mono and disacharides. The disaccharides come off at 315 deg C. Trisaccharides I believe are reported to come off at 350-375 so you need a HT column. I am also told cyanopropyl columns work well and I think Phenomenex makes a HT 1701. Most references I've seen use a db-5.

I am planning to get a HT column next time I replace it so I can do trimaltose.

What about a DB-WAX column?

What about a DB-WAX column?

No- trimethylsilation chemical (excess) from your injection will react with the PEG column phase, and ruin your column.

That's what I thought and the composition is too different from the DB-5. I think I might either just end up doing a alditol acetate derivatization since I already have the column for that or I might try using the DB-5MS for the TMS since the composition is very similar to the DB-5.

or I might try using the DB-5MS for the TMS since the composition is very similar to the DB-5.

Yep, same, MS column likely was just selected as that because it had lower bleed when tested.