Direct chiral separation with Chiralpak AD converted to the reversed-phase mode

Comparative Enantioseparation of Monoterpenes by HPLC on Three Kinds of Chiral Stationary Phases with an On-Line Optical Rotatory Dispersion under Reverse Phase Mode.

“…The columns used were CD-Ph {Heptakis (2,3,6-tri-O-phenyl carbamate)-␤-cyclodextrin, 25¥0.46 cm ID, Shiseido Ltd., Osaka}; Chiralpak AD-H {Amylose (tris 3,5-dimethylphenyl carbamate), 25¥0.46 cm ID, Daicel Inc., Osaka}, and Chiracel OD-H {Cellulose (tris 3,5-dimethylphenyl carbamate), 25¥0.46 cm ID, Daicel Ltd., Osaka}. To use the AD-H and OD-H columns in a reverse phase mode, each column was washed with anhydrous ethanol at 0.5 ml/min overnight (Ning, 1998). Temperature was controlled at 40˚C.…”

“…Furthermore, some racemates that could not be separated in the normal phase could be adequately resolved in the reversed-phase mode. Additionally, the AD column efficiency did not deteriorate during 3 years of operation in the reversedphase mode (Ning, 1998).…”

“…A polar mobile phase of methanol-water or ethanol-water has been widely thought to be the most economical way for preparative enantioseparation under the reverse phase mode. McCarthy (1994), Kummer et al (1996) and Ning (1998) demonstrated that the eluent of the chiralpak AD column (CSP in this study) could be converted from the originally designed normal phase to re-*To whom correspondence should be addressed. Email: tamura@mail.ag.…”

High‐Throughput Screening and Method Development Strategies to Separate Chiral Drug Compounds in HPLC, SFC, and CE

“…The change of elution order is of importance when developing analyses that can be scaled up for preparative purposes and when developing analyses that are used to assay the distomer impurity, because it is important to be able to choose which enantiomer elutes first [57,58]. Besides isocratic elution, there are also rapid NPLC screening strategies in gradient elution mode.…”

Chiral Separation of Organic Phosphonate Compounds on Cellulose CSP (Chiral Stationary Phase) under Reversed Phase Mode

“…1,2 Among these CSPs, Pirkle's and polysaccharide-type CSPs, have proved to be very effective for the determination of the purity and absolute configuration of a variety of enantiomers. 3,4 Recently the chiral separations of some organo-phosphorus compounds were reported on different Pirkle's CSPs: for example, the separation of the enantiomers of a series of diethyl N-(aryl)-1-arylmethanephosphonates on a WHELK-O-column.…”