Effect of column temperature on the behaviour of some angiotensin converting enzyme inhibitors during high-performance liquid chromatographic analysis

Kocijan, Andrej; Grahek, Rok; Kocjan, Darko; Zupančič‐Kralj, Lucija

doi:10.1016/s0378-4347(01)00082-2

Cited by 29 publications

(12 citation statements)

References 10 publications

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“…The elution order of the peaks was assigned according to the findings of Qin et al [95] and Kocijan et al [97] that the predominating cis-enalaprilat has a larger hydrophobic surface area and therefore interacts better with SDS micelles and stationary phases on RP chromatographic columns. Therefore, the elution order of the isomers should be trans before cis according to IUPAC rules [98].…”

Section: Drugsmentioning

confidence: 99%

Investigation of the stereodynamics of molecules and catalyzed reactions by CE

Trapp

2010

Electrophoresis

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The investigation of the molecular dynamics of stereoisomers and the study of the kinetics of reactions, in particular of catalyzed reactions, is of fundamental interest in chemistry, biochemistry, and medicine. Understanding how to control the transition state of a reaction allows for a directed design of new catalysts and benign processes. The integration of reactions and capillary or microchip-based electrophoretic separations is highly attractive to perform on-column derivatizations or enzymatic on-column digests of peptides and proteins for further characterization. The present review article focuses on the recent advances to study the stereodynamics of molecules and reaction kinetics of catalyzed processes by means of CE. Models and algorithms to evaluate interconversion profiles obtained by electrophoretic separation techniques are discussed with respect to the challenging demands of high separation efficiencies typical for electrophoretic techniques. Models used for evaluation are based on iterative computer simulation algorithms using the theoretical plate model or stochastic model of chromatography, empirical calculation methods, derived from equations used in chemical engineering, namely Damköhler analysis, and direct access with the approximation function and more recently with the unified equation, which can be applied to all kinds of first-order reactions taking place during a chromatographic or a electrophoretic separation. Furthermore, areas of applications are presented and discussed to give a guideline for using dynamic CE and on-column reaction electrophoresis to study kinetics of reactions and dynamic processes.

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Section: Drugsmentioning

confidence: 99%

Investigation of the stereodynamics of molecules and catalyzed reactions by CE

Trapp

2010

Electrophoresis

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“…On the other hand, ramipril had a good and stable recovery, but the peak broadening and tailing presented a new problem. Although, it could be solved by using a high column temperature (60 • C) [11], the bonded stationary phases tend to deteriorate rapidly at high column temperatures. Next, we attempted to use daidzein as the I.S., which is also an acid.…”

Section: Lc-ms-ms Analysismentioning

confidence: 99%

Simultaneous determination of enalapril and enalaprilat in human plasma by liquid chromatography–tandem mass spectrometry

Chen

Zhong

et al. 2004

Journal of Chromatography B

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“…It was found that in the investigated temperature range the ratio of the peaks of the two isomers is temperature-dependent and the peak area of the first eluted isomer decreases with increasing temperature. The elution order of the peaks was assigned according to the findings of Qin et al [22] and Kocijan et al [47] that the predominating cis-enalaprilat has a larger hydrophobic surface area and therefore interacts better with SDS micelles and stationary phases on RP chromatographic columns. Therefore, the elution order of the isomers should be trans before cis.…”

Section: Separationmentioning

confidence: 99%

Determination of the cis‐trans isomerization barrier of enalaprilat by dynamic capillary electrophoresis and computer simulation

Trapp

Schurig

2004

Electrophoresis

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Dynamic capillary electrophoresis (DCE) and computer simulation of the elution profiles with the stochastic model has been applied to determine the isomerization barriers of the angiotensin converting enzyme inhibitor enalaprilat. The separation of the rotational cis-trans isomeric drug has been performed in an aqueous 20 mM borate buffer at pH 9.3. Interconversion profiles featuring plateau formation and peak broadening were observed. To evaluate the rate constants k(cis-->trans) and k(trans-->cis) of the cis-trans isomerization from the experimental electropherograms obtained by dynamic capillary electrophoresis, elution profiles were analyzed by a simulation with iterative convergence to the experimental data using the ChromWin software which requires the total migration times of the individual isomers t(R), the electroosmotic break-through time t(0), the plateau height h(plateau), the peak widths at half height of the individual isomers w(h), as well as the peak ratio of the isomers as experimental data input. From temperature-dependent measurements between 0 degrees and 15 degrees C the thermodynamic parameters Delta G, Delta H and Delta S, the rate constants k(cis-->trans) and k(trans-->cis) and the kinetic activation parameters Delta G*, Delta H*, and Delta S* of the cis-trans isomerization of enalaprilat were obtained. From the activation parameters the isomerization barriers at 37 degrees C were calculated to be Delta G* (trans-->cis) = 87.2 kJ.mol(-1) and Delta G*(cis-->trans) = 91.9 kJ.mol(-1).

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Effect of column temperature on the behaviour of some angiotensin converting enzyme inhibitors during high-performance liquid chromatographic analysis

Cited by 29 publications

References 10 publications

Investigation of the stereodynamics of molecules and catalyzed reactions by CE

Investigation of the stereodynamics of molecules and catalyzed reactions by CE

Simultaneous determination of enalapril and enalaprilat in human plasma by liquid chromatography–tandem mass spectrometry

Determination of the cis‐trans isomerization barrier of enalaprilat by dynamic capillary electrophoresis and computer simulation

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