Bile Salts in Chiral Micellar Electrokinetic Chromatography: 2000–2020

Abstract

Bile salts are naturally occurring chiral surfactants that are able to solubilize hydrophobic compounds. Because of this ability, bile salts were exploited as chiral selectors added to the background solution (BGS) in the chiral micellar electrokinetic chromatography (MEKC) of various small molecules. In this review, we aimed to examine the developments in research on chiral MEKC using bile salts as chiral selectors over the past 20 years. The review begins with a discussion of the aggregation of bile salts in chiral recognition and separation, followed by the use of single bile salts and bile salts with other chiral selectors (i.e., cyclodextrins, proteins and single-stranded DNA aptamers). Advanced techniques such as partial-filling MEKC, stacking and single-drop microextraction were considered. Potential applications to real samples, including enantiomeric impurity analysis, were also discussed.

Strategies for capillary electrophoresis: Method development and validation for pharmaceutical and biological applications—Updated and completely revised edition

“…Applications of MEKC are abundant in the literature [31,36,37,[47][48][49][50], and thus only a few examples will be specifically mentioned in this section. Among those, we would like to highlight the applicability of MEKC to develop a microchip CE (MCE) method to differentiate original and seized, adulterated whiskeys.…”

“…TA B L E 3 Surfactants and modifier used in MEKC and/or MEEKC with example literature [18,31,48,50,68,70,[72][73][74].…”

“…Anionic SDS [18,31,70] Lithium dodecyl sulfate, sodium octane sulfonate [18] Bile salts [50] Sodium cholate (bile salt)…”

“…Among the surfactants that enable that possibility, it is worth mentioning polymeric glucopyranoside-based surfactants [82,83]. In addition, it is important to mention that bile salts can not only be used for normal, but also for chiral MEKC separations, supporting the use of co-CSs such as β-cyclodextrins (CDs) [50,84]. However, bile salts can generally cause chiral separation on their own [85], whereas achiral ionic-surfactants such as SDS need a co-CS [74].…”

New Trends in the Quality Control of Enantiomeric Drugs: Quality by Design-Compliant Development of Chiral Capillary Electrophoresis Methods

“…The use of additives to enhance/modulate CD-driven chiral separations has been known for a long time, and CD-modified micellar electrokinetic chromatography (CD-MEKC) [ 97 , 98 ] as well as CD-modified microemulsion electrokinetic chromatography (CD-MEEKC) [ 99 ] can be included in this strategy. Recently chiral ILs have been the focus of an intense interest as additives for their synergistic effect on CD-driven enantioseparations [ 100 , 101 , 102 , 103 , 104 , 105 , 106 , 107 , 108 , 109 , 110 , 111 , 112 ], and in some instances, for functionalization of the CDs [ 113 , 114 ].…”