Evaluation of non-conventional polar modifiers on immobilized chiral stationary phases for improved resolution of enantiomers by supercritical fluid chromatography.
An evaluation of the use of non-conventional polar modifiers for the supercritical fluid chromatographic separation of enantiomers on immobilized chiral stationary phases is presented. The resolution of a group of nine commercially available racemates is studied on the Chiralpak IA, IB, IC, ID, IE, and IF chiral stationary phases using CO2-based eluents containing non-conventional polar modifiers such as dichloromethane, chloroform, tetrahydrofuran, 2-methyl tetrahydrofuran, methyl tert-butyl ether, cyclopentyl methyl ether, acetone, ethyl acetate, toluene, 2,2,2-trifluoroethanol, and N,N-dimethylformamide. Screening experiments and method development for the commercial racemates on the immobilized columns with the non-conventional solvents demonstrated an ability to adjust the retention and improve resolution. From these results we were able to assign a general eluotropic relationship between the non-conventional solvents and methanol. A general ability to selectively adjust chromatographic retention while improving analyte solubility can lead to improved preparative chromatographic performance.
Merck Research Laboratories, Rahway, NJ 07065, USA. Electronic address: jimmy.dasilva@merck.com.
Jimmy O
JO
DaSilva
Merck Research Laboratories, Rahway, NJ 07065, USA.
Brandyce
B
Coes
Merck Research Laboratories, Rahway, NJ 07065, USA.
Lisa
L
Frey
Merck Research Laboratories, Rahway, NJ 07065, USA.
Ingrid
I
Mergelsberg
Merck Research Laboratories, West Point, PA 19486, USA.
Ray
R
McClain
Merck Research Laboratories, Boston, MA 02115, USA.
Lisa
L
Nogle
Merck Research Laboratories, Rahway, NJ 07065, USA.
Christopher J
CJ
Welch
D002851:Chromatography, High Pressure Liquid / Q000379:methods; D025924:Chromatography, Supercritical Fluid / Q000379:methods; D004364:Pharmaceutical Preparations / Q000032:analysis*; D012997:Solvents / Q000737:chemistry*; D013237:Stereoisomerism
D004364:Pharmaceutical Preparations; D012997:Solvents
Analytical; Chiral; Chromatography; Columns; Preparative; SFC