Measurement of thermodynamic quantities of micellar solubilization by micellar electrokinetic chromatography with sodium dodecyl sulfate

Terabe, Shigeru; Katsura, Takehisa; Okada, Yukihirao; Ishihama, Yasushi; Otsuka, Koji

doi:10.1002/mcs.1220050104

Cited by 86 publications

(56 citation statements)

References 14 publications

(26 reference statements)

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“…Due to a higher electric current with the 100 mM SDS electrolyte system, the mean temperature in the capillary will increase. This will cause a decrease of distribution constants and retention factors of the sample compounds [18,19]. In Fig.…”

Section: Buffer Ph and Ionic Strengthmentioning

confidence: 99%

Parameters controlling the elution window and retention factors in micellar electrokinetic capillary chromatography

Muijselaar

Claessens

Cramers

1995

Journal of Chromatography A

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Section: Buffer Ph and Ionic Strengthmentioning

confidence: 99%

Parameters controlling the elution window and retention factors in micellar electrokinetic capillary chromatography

Muijselaar

Claessens

Cramers

1995

Journal of Chromatography A

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“…This means that the amino acid enantiomers migrate slowly than the EOF, because analytes are slowed down by negatively charged micellar phases, which migrate in the opposite direction. Further, the partition coefficients of Phe and Trp were calculated to be 398 and 754 in a pH 4.6 phosphate buffer containing 10 mM SDS, based on following equations: 32 (5) (6) where V is the partial specific volume of the micelle, 0.25 dm 3 /mol for SDS. 32 [Surf] is the surfactant concentration used (10 mM).…”

mentioning

confidence: 99%

“…Further, the partition coefficients of Phe and Trp were calculated to be 398 and 754 in a pH 4.6 phosphate buffer containing 10 mM SDS, based on following equations: 32 (5) (6) where V is the partial specific volume of the micelle, 0.25 dm 3 /mol for SDS. 32 [Surf] is the surfactant concentration used (10 mM). cmc is the critical micelle concentration, determined to be 2.97 in the running electrolytes with SDS.…”

mentioning

confidence: 99%

Reversal Behaviors of the Enantiomer Migration Order and the Stereo-selectivity of Cu(II) Complex with Amino Acid Enantiomers in Ligand Exchange-Micellar Electrokinetic Chromatography

et al. 2000

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Since the pioneering work of Terabe et al. 1,2 micellar electrokinetic chromatography (MEKC) has become a powerful technique for the analysis of both neutral and charged samples. 3 Many researchers focus their work on the development of novel methods concerning MEKC by using modifiers. For example, cyclodextrin-modified MEKC (CD-MEKC) 4-7 borate-complex EKC 8,9 and ion-exchange EKC 10,11 have been reported. Each of these methods has extended the application of MEKC to the analysis of various types of compounds. The mechanism of the ligand exchange was reported for the separation of dansyl amino acid enantiomers by liquid chromatography 12,13 and subsequently capillary electrophoresis. 13,14 Ligand exchange-micellar electrokinetic chromatography (LE-MEKC), a hybrid technique of the ligand exchange mechanism and MEKC, has been receiving increasing attention, because it offers the possibility of the simultaneous separation of optical isomers with the differences in the positional structure, such as o-, m-, p-enantiomers of amino acids, which contain a phenyl ring with different substituents 16 as well as positional and optical isomers of the tryptophan family. 17 Based on the ligand exchange mechanism, it is the difference in the stability constants that give the chiral separation of enantiomers. In other words, the EMO depends on the stability of the complex. Therefore, EMO can be predicted based on the stability of the complex. Conversely, the EMO can be applied in a study of complex stability.In order to explore the mechanism of LE-MEKC and to provide some scientific evidence for predicting and controlling the EMO or for studying the complex stability of a ternary Cu(II) complex with different amino acid enantiomers, it is significant to study the separation behavior of enantiomers in LE-MEKC. In fact, many works have thrown light on the reversal of the EMO. 14,15,18-22 Our previous work involved the separation behavior of amino acid enantiomers in LE-MEKC, 23 in which we discussed the reversal of EMO of amino acids and o-, m-and p-order of enantiomers with the introduction of micellar phases. In this paper we focus our study on the influence of ligand chirality, trans-and cis-conformation of 4-hydroxy group in hydroxyproline and the SDS micellar phase on the separation behavior when using different ligands of the proline family in LE-MEKC. Experimental InstrumentationThe CE instrumental setup involves a HEL5-30P2-TTu high voltage power supply (Matsusada Precision Devices Inc., Japan), a CE-971 UV detector (Jasco Corporation, Japan) and a C-R6A Chromatopac Recorder (Shimadzu, Japan). Separations were carried out in fused-silica capillaries (0.050 mm i.d.×0.375 mm o.d.) from GL Sciences Inc. (Japan) with a total length of 56 cm and an effective length of 40 cm. ChemicalsAll of the chemicals were of reagent grade and were used as Hachioji, Japan The dependence of the enantioselectivity and enantiomer migration order (EMO) on the chirality and stereo-conformation of ligands used for the chiral selectors of Cu(...

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“…Furthermore, a linear relationship was obtained between DH8 and DS8 in the micellar solubilization of drugs [37]. The compensation temperature [38] was equal to the slope of the line. Melander and Hatvath compared this temperature value with values found in reversed phase high performance liquid chromatography (RPLC) [39].…”

Section: Interactions Between Drugs and Micellesmentioning

confidence: 99%

Use of affinity capillary electrophoresis for characterizing pharmaceutical colloidal vehicle systems thermodynamically

Neubert¹,

Mrestani²

2001

Biopharm & Drug Disp

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This review offers a detailed discussion of the interaction between pharmaceutical compounds and vehicles using the affinity capillary electrophoresis and the microemulsion electrokinetic chromatography. Partition coefficients of drugs were calculated between a micelle and an aqueous phases from the measurement of the migration time, provided the critical micelle concentration and the phase ratio are known. Thermodynamic quantities such as enthalpy and entropy changes of micellar solubilization were calculated from the temperature dependence of the partition coefficients. Partial specific volumes were measured using dynamic light scattering. The logarithm of the partition coefficients and the capacity factor in the micellar system were correlated with the logarithm of the n-octanol/water partition coefficients.

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Measurement of thermodynamic quantities of micellar solubilization by micellar electrokinetic chromatography with sodium dodecyl sulfate

Cited by 86 publications

References 14 publications

Parameters controlling the elution window and retention factors in micellar electrokinetic capillary chromatography

Parameters controlling the elution window and retention factors in micellar electrokinetic capillary chromatography

Reversal Behaviors of the Enantiomer Migration Order and the Stereo-selectivity of Cu(II) Complex with Amino Acid Enantiomers in Ligand Exchange-Micellar Electrokinetic Chromatography

Use of affinity capillary electrophoresis for characterizing pharmaceutical colloidal vehicle systems thermodynamically

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