pH stability of Daicel chiral stationary phases
Posted: Wed Feb 06, 2008 11:22 am
hello
instruction manuals for OD-RH and OJ-RH from Daicel reccomend to use these columns between pH 2 and 7.
AD-RH can be used up to pH 9 instead (again, according to the manual)
the stationary support is the same for all of them (silica). the only difference is the back-bone of the stationary phase which is amylose (od-rh and oj-rh), or cellulose (ad-rh).
now i think that cellulolose and amylose are affected by extreme pH in basically the same way, therefore this can't be the difference. even the derivatizing group attached to the polysaccharide backbone can't play a role, because ad-rh and od-rh have the same one (3,5-dimethylephenylcarbamate).
so, has anybody an explanation for the different pH stability range?
thanks!
M.
instruction manuals for OD-RH and OJ-RH from Daicel reccomend to use these columns between pH 2 and 7.
AD-RH can be used up to pH 9 instead (again, according to the manual)
the stationary support is the same for all of them (silica). the only difference is the back-bone of the stationary phase which is amylose (od-rh and oj-rh), or cellulose (ad-rh).
now i think that cellulolose and amylose are affected by extreme pH in basically the same way, therefore this can't be the difference. even the derivatizing group attached to the polysaccharide backbone can't play a role, because ad-rh and od-rh have the same one (3,5-dimethylephenylcarbamate).
so, has anybody an explanation for the different pH stability range?
thanks!
M.