Enantiomeric Separations of Cationic and Neutral Compounds by Capillary Electrochromatography with Charged Polyacrylamide Gels Incorporating Chiral Selectors

Chiral separation by chromatographic and electromigration techniques. A Review

“…Koide and Ueno [530] prepared monolithic CSPs by incorporating b-CD polymers such as poly b-CD and CM-b-CD polymer in a polyacrylamide gel or by in situ polymerization of allyl carbamoylated b-CD (AC-b-CD), acrylamide, N,N 0 -methylenebisacrylamide and N-(2-acrylamidoethyl) triethylammonium iodide, in the presence of N,N,N 0 ,N 0 -tetramethylethylendiamine and ammonium peroxodisulfate in the capillary [531]. Recently, the same group developed a monolithic CSP containing a chiral crown ether, which was applied to the chiral separation of compounds containing primary amino groups [532].…”

Enantiomeric Separations by Capillary Electrochromatography with Charged Polyacrylamide Gels Incorporating Chiral Selectors

“…We then used poly-β-CD and CM-β-CD polymer called polymeric β-CDs, which are of large molecular weight, as chiral selectors, as described in our previous paper. 36 The mechanism by which chiral selectors were immobilized inside the capillaries was presumed that chiral selectors of large molecular weight could twine around the gels. Poly-β-CD is a neutral compound, while CM-β-CD polymer is an anionic compound with carboxyl groups.…”

“…Based on the results of our work, 36 we prepared negatively charged polyacrylamide gel-filled capillaries (8%T, 5%C, 5.5%S) incorporating poly-β-CD and CM-β-CD polymer, to which 5% (v/v) Tween 20 had been added to make the resulting gels transparent and elastic and to obtain high efficiencies. The mobile phases were 200 mmol dm -3 Tris-300 mmol dm -3 boric acid buffer (pH 8.1 and 9.0).…”

“…35 We also reported novel enantiomeric separation methods of CEC with monolithic CSPs. [36][37][38][39] This paper reports successful enantiomeric separations of various compounds by CEC using negatively or positively charged polyacrylamide gels incorporating polymeric β-CDs as chiral selectors.…”

Enantiomeric Separations of Cationic and Neutral Compounds by Capillary Electrochromatography with β-Cyclodextrin-Bonded Charged Polyacrylamide Gels

“…Very recently, the enantiomeric separation of N- (3,5-dinitrobenzoyl)leucine diallylamide was obtained using monolithic chiral stationary phases for CEC prepared within the confines of untreated fused-silica capillaries by the direct copolymerization of the chiral monomer 2-hydroxyethyl methacrylate (N-L-valine-3,5-dimethylanilide) carbamate with ethylene dimethacrylate, 2-acrylamido-2-methylpropanesulfonic acid and butyl or glycidyl methacrylate in the presence of a porogenic solvent. 9 In our previous paper 10 , the enantiomeric separations of cationic and neutral compounds by CEC using a charged polyacrylamide gel as a monolithic stationary phase, in which polymeric β-cyclodextrins (β-CD) as chiral selectors are immobilized by incorporation, were reported. Unfortunately, no enantiomeric separation was achieved using monomeric β-CD, because it was eluted out of the capillary column by electroosmotic flow (EOF) to the cathodic solution during preelectrophoresis.…”