Fundamental aspects of field-amplified electrokinetic injection of cations for enantioselective capillary electrophoresis with sulfated cyclodextrins as selectors

Contemporary chiral simulators for capillary zone electrophoresis

“…SIMUL5complex and GENTRANS provide the full dynamics of any buffer and sample arrangement and require very long execution time intervals (days to weeks for realistic configurations employed in CZE). They represent valuable research tools and provide detailed insight on the formation and behavior of boundaries and zones, including those occurring during sample stacking and destacking in CZE, as well as those produced in the discontinuous buffer systems used in ITP and IEF . PeakMaster 6 is restricted to conventional CZE in which a small amount of sample is introduced at the beginning of a capillary and then electrophoresed into a BGE of uniform composition and is based on an approximate solution of the transport equations .…”

“…SIMUL5complex was used to elucidate the impact of the complexation of buffer constituents with neutral agents on common buffer properties and analyte and system peaks in CZE , and to provide insight into the sweeping process of a drug in presence of a neutral CD . Furthermore, the fundamentals of field‐amplified electrokinetic injection of cations for enantioselective CZE with sulfated β‐cyclodextrin (S‐β‐CD) , the characterization of isomer mixtures of S‐β‐CD , the investigation of the enantioselective separation of weak bases in an on‐line CZE microanalysis configuration comprising S‐β‐CD as selector , and the exploration of inverse cationic ITP for separation of methadone enantiomers with S‐β‐CD as chiral selector were also studied with this simulator. The MEKC behavior of neutral analytes in presence of SDS and the comparison of transient trapping with sweeping in MEKC with SDS were investigated with GENTRANS.…”

Computer simulation of the enantioselective separation of weak bases in an online capillary electrophoresis based microanalysis configuration comprising sulfated cyclodextrin as selector

“…As initial concentration profiles, GENTRANS data obtained after mixing (see Fig. 4A in ) were reduced to 1000 data points each employing the filter function of Excel (Microsoft, Redmond, WA, USA), converted into a binary concentration file and imported into SIMUL5complex using our own software program that was created in LabVIEW (National Instruments, Austin, TX, USA; see for details). The reaction mixture consisted of ketamine, reduced β‐nicotinamide adenine dinucleotide phosphate (NADPH), and the CYP3A4 enzyme in the incubation buffer (IB) comprising 161 mM KOH and 100 mM H 3 PO 4 at pH 7.4.…”

“…To simulate the separation, the IB in a 1 cm part of the inlet end of the 10 cm column was replaced with BGE composed of 50 mM Tris, 77 mM H 3 PO 4 with 7.6 mM (2.0%) HS‐γ‐CD, and 98.8 mM sodium at pH 2.5. This represents changing the inlet buffer vial from IB to BGE and the concentration profiles were adapted accordingly with our own software program . The resulting configuration consisting of the reaction mixture in IB (between 10 and approximately 55 mm of column length) bracketed by BGE is shown in the top panels of Fig.…”

Enantioselective capillary electrophoresis for pharmacokinetic analysis of methadone and 2‐ethylidene‐1,5‐dimethyl‐3,3‐diphenylpyrrolidine in equines anesthetized with ketamine and isoflurane

“…It provides higher efficiency and is simpler, faster, more environmentally friendly and less expensive than HPLC and LC‐MS. The concentration sensitivity, however, is typically lower compared to that in chromatographic methods but can be circumvented by employing techniques that enable analyte stacking . While it is straightforward to separate methadone enantiomers by CE in presence of neutral cyclodextrins, resolution of the EDDP stereoisomers is difficult with these chiral selectors .…”