Chiral Separations in Nonaqueous Media - Chiral Separations by Capillary Electrophoresis - page 304

BGE containing the chiral selector. For a recent review on NACE-MS hyphenation
see the reference [106].

10.7 CONCLUDING REMARKS
Since the majority of the chiral drugs that are introduced into the market today are
produced in an enantiomerically pure form [108], there is a need for accurate and
rapid determination of chiral impurity. The high peak capacity of CE, makes it a
promising technique for the conduction of such determinations, since it is highly
efi cient and has a sufi cient LOD for this type of applications [12]. The use of non-
aqueous media in CE is preferable especially for purity determination of solutes with
a low solubility in water. Chiral NACE has also proved its usefulness for biologi-
cal applications, particularly in combination with the hyphenation to MS detection
[22], e.g., for studies of chiral metabolism or chiral kinetics. Chiral CE is especially
valuable for studies where the sample amount is limited, e.g., in samples from small
children or laboratory animals, when CE could be used as an alternative to HPLC.
Nonaqueous solvents facilitate the use of ion-pair selectors for chiral separations
in CE, and different selectivities compared to aqueous systems are obtained for the
CDs and the CD derivatives. Although, the separation mechanism in HPLC (using a
CSP) and in CE differs, the use of chiral NACE has been demonstrated to facilitate
rapid screening of new potential chiral selectors for HPLC.

LIST OF ABBREVIATIONS
(−)-DIKGA (−)-2,3:4,6 -Di- O -isopropylidene-2-keto-l-gulonic acid

ACN acetonitrile

Ad-CQN 1-adamantyl carbamoylated quinine

Ala-ala alanine-alanine

All-CNHQD allyl carbamolylated dihydroquinidine

ALL-CNHQN allyl carbamoylated dihydroquinine

BGE background electrolyte

C8-acid octanoic acid

CD cyclodextrin

CE capillary electrophoresis

cHex-bisCQN trans -1,4-cyclohexylene(carbamoylated quinine)

cHex-bis-
CQN-S-C12

trans -1,4-cyclohexylene-bis(carbamoylated-11-dodecylthio-
dihydroquinine)

cHex-bis-
CQN-SO-C12

trans -1,4-cyclohexylene-bis(carbamoylated-11-dodecylsuli nyl-
dihydroquinine)

cHex-CCD cyclohexyl cinchonidine

CMPA chiral mobile phase additive

CSP chiral stationary phase

CSS camphersulfonic acid

DCM dichloromethane

DCP-CQD 3,4-dichlorophenyl carbamoylated quinidine