Investigation of cross-linking chiral stationary phases within capillary columns - Lou, X.; Liu, Y.; Zhou, L. (Elsevier)
Four diamide chiral stationary phases (CSPs), undecenoyl-l-valine-(S)-α-phenhylethylamide (CSP-1), OV-225-l-valine-tert.-butylamide (CSP-2), Xe-60-l-valine-tert.-butylamide (CSP-3) and polycyanoethyl vinyl siloxane 25% cyanoethyl-l-valine-tert.-butylamide, were cross-linked within both glass and fused-silica capillary columns with dibenzoyl peroxide (DBP) as the cross-linking reagent. The effects of the CSP skeleton on the degree of cross-linking and racemization (decrease in enantiomeric excess) of the stationary phase during cross-linking were investigated. The performance of the cross-linked columns in terms of enantioselectivity, thermal stability, acid-based characteristics and column efficiency were determined and compared and compared. The results show that the CSP skeleton may have considerable effects on both cross-linking and racemization.
http://linkinghub.elsevier.com/retrieve/pii/S0021-9673(01)95929-1
Keywords: V