1
|
Separability of stereoisomers by electrokinetic chromatography in presence of a neutral selector – fundamental aspects assessed by computer simulation. J Chromatogr A 2022; 1673:463087. [DOI: 10.1016/j.chroma.2022.463087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 04/18/2022] [Accepted: 04/20/2022] [Indexed: 11/23/2022]
|
2
|
Theurillat R, Stirnimann G, Wenker C, Hoby S, Thormann W. Aspects of albendazole metabolism in western lowland gorillas (
Gorilla gorilla gorilla
) compared to humans and other species assessed by HPLC, LC‐MS, and chiral electrokinetic chromatography. SEPARATION SCIENCE PLUS 2021. [DOI: 10.1002/sscp.202100024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Regula Theurillat
- Clinical Pharmacology Laboratory Institute for Infectious Diseases University of Bern Bern Switzerland
| | - Guido Stirnimann
- University Clinic for Visceral Surgery and Medicine University Hospital Inselspital and University of Bern Bern Switzerland
| | | | | | - Wolfgang Thormann
- Clinical Pharmacology Laboratory Institute for Infectious Diseases University of Bern Bern Switzerland
| |
Collapse
|
3
|
Thormann W, Mosher RA. Dynamic computer simulations of electrophoresis: 2010-2020. Electrophoresis 2021; 43:10-36. [PMID: 34287996 PMCID: PMC9292373 DOI: 10.1002/elps.202100191] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 07/12/2021] [Accepted: 07/15/2021] [Indexed: 02/05/2023]
Abstract
The transport of components in liquid media under the influence of an applied electric field can be described with the continuity equation. It represents a nonlinear conservation law that is based upon the balance laws of continuous transport processes and can be solved in time and space numerically. This procedure is referred to as dynamic computer simulation. Since its inception four decades ago, the state of dynamic computer simulation software and its use has progressed significantly. Dynamic models are the most versatile tools to explore the fundamentals of electrokinetic separations and provide insights into the behavior of buffer systems and sample components of all electrophoretic separation methods, including moving boundary electrophoresis, CZE, CGE, ITP, IEF, EKC, ACE, and CEC. This article is a continuation of previous reviews (Electrophoresis 2009, 30, S16–S26 and Electrophoresis 2010, 31, 726–754) and summarizes the progress and achievements made during the 2010 to 2020 time period in which some of the existing dynamic simulators were extended and new simulation packages were developed. This review presents the basics and extensions of the three most used one‐dimensional simulators, provides a survey of new one‐dimensional simulators, outlines an overview of multi‐dimensional models, and mentions models that were briefly reported in the literature. A comprehensive discussion of simulation applications and achievements of the 2010 to 2020 time period is also included.
Collapse
Affiliation(s)
- Wolfgang Thormann
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | | |
Collapse
|
4
|
Caslavska J, Thormann W. Bioanalysis of drugs and their metabolites by chiral electromigration techniques (2010-2020). Electrophoresis 2021; 42:1744-1760. [PMID: 33570170 DOI: 10.1002/elps.202000383] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 02/03/2021] [Accepted: 02/04/2021] [Indexed: 12/11/2022]
Abstract
The further development and application of capillary electromigration techniques for the enantioselective determination of drugs and their metabolites in body fluids, tissues, and in vitro preparations during the 2010 to 2020 time period continued to proof their usefulness and attractiveness in bioanalysis. This review discusses the principles and important aspects of capillary electrophoresis- based chiral drug bioassays, provides a survey of the assays reported during the past 10 years and presents an overview of the key achievements encountered in that time period. For systems with charged chiral selectors, special attention is paid on assays that feature field-amplified sample injection to enable the determination of ppb levels of analytes and optimized online incubation procedures for the rapid assessment of a metabolic pathway. Applications discussed encompass the pharmacokinetics of drug enantiomers in vivo and in vitro, the impact of inhibitors on metabolic steps, the elucidation of the stereoselectivity of drug metabolism in vivo and in vitro, and drug enantiomers in toxicological, forensic, and doping analysis.
Collapse
Affiliation(s)
- Jitka Caslavska
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Wolfgang Thormann
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| |
Collapse
|
5
|
Caslavska J, Thormann W. Contemporary chiral simulators for capillary zone electrophoresis. Electrophoresis 2019; 41:502-513. [PMID: 31702052 DOI: 10.1002/elps.201900363] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 10/25/2019] [Accepted: 11/01/2019] [Indexed: 11/09/2022]
Abstract
For separation of enantiomers in presence of a chiral selector, data obtained with the 1D dynamic simulators SIMUL5complex and GENTRANS are compared to data predicted by PeakMaster 6, a recently released generalized model of the linear theory of electromigration. Four electrophoretic systems with stereoisomers of weak bases were investigated. They deal with the estimation of input data for complexation together with the elucidation of the origin of observed system peaks, the interference of analyte and system peak migration, the change of enantiomer migration order as function of the selector concentration and the inversion of analyte migration direction in presence of a multiply negatively charged selector. For all systems, data predicted with PeakMaster 6 are in agreement with those of the dynamic simulators and simulation data compare well with experimental data that were monitored with setups featuring conductivity and/or UV absorbance detection along the capillary. SIMUL5complex and GENTRANS provide the full dynamics of any buffer and sample arrangement and require very long execution time intervals. PeakMaster 6 is restricted to conventional CZE, is based on an approximate solution of the transport equations, provides data for realistic experimental conditions within seconds and represents a practical tool for an experimentalist.
Collapse
Affiliation(s)
- Jitka Caslavska
- Clinical Pharmacology Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Wolfgang Thormann
- Clinical Pharmacology Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| |
Collapse
|
6
|
Pires BC, Coelho JF, Silva CF, Dutra FV, Guimarães L, Nascimento CS, Borges KB. Enantioselective separation of bupropion and its major metabolite hydroxybupropion: An experimental and theoretical study. Chem Phys Lett 2019. [DOI: 10.1016/j.cplett.2019.05.035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
7
|
Yu F, Zhao Q, Zhang D, Yuan Z, Wang H. Affinity Interactions by Capillary Electrophoresis: Binding, Separation, and Detection. Anal Chem 2018; 91:372-387. [PMID: 30392351 DOI: 10.1021/acs.analchem.8b04741] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Fangzhi Yu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology , Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing , 100085 , China.,University of Chinese Academy of Sciences , Beijing , 100049 , China
| | - Qiang Zhao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology , Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing , 100085 , China.,University of Chinese Academy of Sciences , Beijing , 100049 , China
| | - Dapeng Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology , Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing , 100085 , China
| | - Zheng Yuan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology , Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing , 100085 , China.,University of Chinese Academy of Sciences , Beijing , 100049 , China
| | - Hailin Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology , Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing , 100085 , China.,University of Chinese Academy of Sciences , Beijing , 100049 , China
| |
Collapse
|
8
|
Mikkonen S, Caslavska J, Gebauer P, Thormann W. Inverse cationic ITP for separation of methadone enantiomers with sulfated β-cyclodextrin as chiral selector. Electrophoresis 2018; 40:659-667. [PMID: 30311251 DOI: 10.1002/elps.201800387] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 10/03/2018] [Accepted: 10/10/2018] [Indexed: 12/17/2022]
Abstract
Chiral ITP of the weak base methadone using inverse cationic configurations with H+ as leading component and multiple isomer sulfated β-CD (S-β-CD) as leading electrolyte (LE) additive, has been studied utilizing dynamic computer simulation, a calculation model based on steady-state values of the ITP zones, and capillary ITP. By varying the amount of acidic S-β-CD in the LE composed of 3-morpholino-2-hydroxypropanesulfonic acid and the chiral selector, and employing glycylglycine as terminating electrolyte (TE), inverse cationic ITP provides systems in which either both enantiomers, only the enantiomer with weaker complexation, or none of the two enantiomers form cationic ITP zones. For the configuration studied, the data reveal that only S-methadone migrates isotachophoretically when the S-β-CD concentration in the LE is between about 0.484 and 1.113 mM. Under these conditions, R-methadone migrates zone electrophoretically in the TE. An S-β-CD concentration between about 0.070 and 0.484 mM results in both S- and R-methadone forming ITP zones. With >1.113 mM and < about 0.050 mM of S-β-CD in the LE both enantiomers are migrating within the TE and LE, respectively. Chiral inverse cationic ITP with acidic S-β-CD in the LE is demonstrated to permit selective ITP trapping and concentration of the less interacting enantiomer of a weak base.
Collapse
Affiliation(s)
- Saara Mikkonen
- Clinical Pharmacology Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland.,Division of Applied Physical Chemistry, Department of Chemistry, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Jitka Caslavska
- Clinical Pharmacology Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Petr Gebauer
- Institute of Analytical Chemistry of the Czech Academy of Sciences, Brno, Czech Republic
| | - Wolfgang Thormann
- Clinical Pharmacology Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| |
Collapse
|
9
|
Chen J, Wang X, Ghulam M, Chen H, Qu F. Predefine resolution of enantiomers in partial filling capillary electrophoresis and two discontinuous function plugs coupling in-capillary. Electrophoresis 2018; 39:2391-2397. [DOI: 10.1002/elps.201800154] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 06/04/2018] [Accepted: 06/24/2018] [Indexed: 12/17/2022]
Affiliation(s)
- Jin Chen
- School of Life Science; Beijing Institute of Technology; Beijing P. R. China
| | - Xiaoqian Wang
- School of Life Science; Beijing Institute of Technology; Beijing P. R. China
| | - Murtaza Ghulam
- School of Life Science; Beijing Institute of Technology; Beijing P. R. China
| | - Hongxu Chen
- School of Life Science; Beijing Institute of Technology; Beijing P. R. China
| | - Feng Qu
- School of Life Science; Beijing Institute of Technology; Beijing P. R. China
| |
Collapse
|
10
|
Chankvetadze B. Contemporary theory of enantioseparations in capillary electrophoresis. J Chromatogr A 2018; 1567:2-25. [PMID: 30025609 DOI: 10.1016/j.chroma.2018.07.041] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 07/05/2018] [Accepted: 07/12/2018] [Indexed: 11/17/2022]
Abstract
The first separation of enantiomers in capillary electrophoresis (CE) counts slightly longer than three decades. Fast development of the practice and theory of chiral CE occurred in the past 30 years and today one can consider this technology to have a solid and mature theoretical background. The goal of the present review is not only to summarize the history and contemporary theory of enantioseparations by using CE but also to present the authors personal view where shall we head to with this attractive technology not only from the viewpoint of separation of enantiomers but also for better understanding the mechanisms of non-covalent (enantioselective) interactions in chemistry, biology, medicine and related disciplines.
Collapse
Affiliation(s)
- Bezhan Chankvetadze
- Institute of Physical and Analytical Chemistry, School of Exact and Natural Sciences, Tbilisi State University, Chavchavadze Ave 1, 0179 Tbilisi, Georgia.
| |
Collapse
|
11
|
Šesták J, Theurillat R, Sandbaumhüter FA, Thormann W. Fundamental aspects of field-amplified electrokinetic injection of cations for enantioselective capillary electrophoresis with sulfated cyclodextrins as selectors. J Chromatogr A 2018; 1558:85-95. [PMID: 29759647 DOI: 10.1016/j.chroma.2018.05.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 05/02/2018] [Accepted: 05/08/2018] [Indexed: 01/30/2023]
Abstract
Head-column field-amplified sample stacking of cations from a low conductivity sample followed by enantiomeric separation using negatively charged chiral selectors was studied experimentally and with computer simulation. Aspects investigated include the direct electrokinetic injection of the analytes into the background electrolyte, the use of a selector free buffer plug, the contribution of complexation within the buffer plug and the application of an additional water plug between sample and buffer plug. Attention was paid for changes of ionic strength which is known to have a significant impact on complexation and thus effective mobility. Racemic methadone was selected as a model compound, randomly substituted sulfated β-cyclodextrin as chiral selector and phosphate buffers (pH 6.3) for the background electrolyte and the buffer plug. Results confirm that the buffer plug is providing a spacer between cationic analytes and the negatively charged selector during electrokinetic injection. Simulation predicts the required length and composition of the plug for a given injection time to avoid an interference with the selector. A short water plug added between the low conductivity sample and a high conductivity buffer plug is demonstrated to provide best conditions to achieve high sensitivity in enantioselective drug assays with sulfated cyclodextrins as selectors.
Collapse
Affiliation(s)
- Jozef Šesták
- University of Bern, Clinical Pharmacology Laboratory, Institute for Infectious Diseases, Murtenstrasse 35, 3008 Bern, Switzerland; Institute of Analytical Chemistry of the Czech Academy of Sciences, Veveří 97, 602 00 Brno, Czechia
| | - Regula Theurillat
- University of Bern, Clinical Pharmacology Laboratory, Institute for Infectious Diseases, Murtenstrasse 35, 3008 Bern, Switzerland
| | - Friederike A Sandbaumhüter
- University of Bern, Clinical Pharmacology Laboratory, Institute for Infectious Diseases, Murtenstrasse 35, 3008 Bern, Switzerland
| | - Wolfgang Thormann
- University of Bern, Clinical Pharmacology Laboratory, Institute for Infectious Diseases, Murtenstrasse 35, 3008 Bern, Switzerland.
| |
Collapse
|
12
|
Mikkonen S, Thormann W. Computer simulation of the enantioselective separation of weak bases in an online capillary electrophoresis based microanalysis configuration comprising sulfated cyclodextrin as selector. Electrophoresis 2018; 39:1482-1487. [PMID: 29645297 DOI: 10.1002/elps.201800113] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 03/29/2018] [Accepted: 04/03/2018] [Indexed: 11/10/2022]
Abstract
Computer simulation was utilized to characterize the electrophoretic processes occurring after reactant mixing in an online assay format used for monitoring the enantioselective N-demethylation of ketamine to norketamine in the presence of highly sulfated γ-cyclodextrin (HS-γ-CD). The incubated reaction mixture (at pH 7.4 and without chiral selector) is bracketed by a low pH BGE containing 2% HS-γ-CD as chiral selector, thereby forming a discontinuous buffer system. Upon power application, simulation provides insight into the formation of moving boundaries and new zones together with the prediction of the behavior of ketamine and norketamine enantiomers. The analytes first migrate cationically in a zone electrophoretic manner until they come in contact with HS-γ-CD upon which enantioseparation is initiated. Complexation has a focusing effect and the electrophoretic transport becomes reversed, that is, toward the anode. Simulation revealed that the initial conditions for the chiral separation, including buffer components concentrations, pH, and ionic strength, are different than those in the BGE. As a consequence thereof, the experimentally determined complexation parameters for the BGE were unable to correctly describe the migration behavior of the analytes in this column section. An increase in the input binding constants by a factor of two to four, as a result of the decreased ionic strength, resulted in simulation data that agreed with experimental findings.
Collapse
Affiliation(s)
- Saara Mikkonen
- Clinical Pharmacology Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Wolfgang Thormann
- Clinical Pharmacology Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| |
Collapse
|