Open tubular CE for in vitro oxidation studies of human very-low-density lipoprotein particles.

Human very-low-density lipoprotein (VLDL) particles were immobilised on the inner wall of electrochromatographic fused-silica capillaries, and the applicability of these capillary columns in oxidation studies was investigated. Capillaries coated with radiolabelled VLDL particles showed a coating efficiency of 97%, and allowed estimation of the amount of VLDL present in a capillary. Radioactivity measurements and atomic force microscopy with tapping mode confirmed the presence of VLDL particles as a monolayer.

Open tubular capillary electrochromatography: technique for oxidation and interaction studies on human low-density lipoproteins.

A novel, open tubular capillary electrochromatographic method was developed for the in vitro oxidation of low-density lipoprotein (LDL) particles. Low-density lipoprotein particles with molar mass of approximately 2.5 MDa yielded a stable stationary phase at temperatures 25 and 37 degrees C and at pH values from 3.

Human low-density lipoprotein-coated capillaries in electrochromatography.

Low-density lipoprotein (LDL) particles were immobilized on the inner wall of a fused-silica capillary and used in a study of the interactions between LDL and neutral drugs in electrochromatography. The effect of coating parameters (pH, ionic strength of the coating solution, duration of the coating procedure) on the properties and stability of the coating was examined. The stability of the coating was highest when the pH of the coating solution was under the pI value of the LDL particles.

Capillary zone electrophoresis of cationic and anionic drugs in methanol.

The actual mobilities and dissociation constants of acidic and basic pharmaceuticals were determined in methanol. Actual mobilities were derived from the dependence of the effective mobilities of the analytes on the pH of the methanolic background electrolyte solution (pH(MeOH)). The pKa values of the pharmaceuticals in methanol (pK(a,MeOH)) were calculated by non-linear curve fitting to the measured mobility values.

Influence of cetyltrimethylammonium bromide on phosphatidylcholine-coated capillaries.

Large unilamellar vesicles of egg-phosphatidylcholine (eggPC), a naturally occurring phospholipid, were used in capillary electrophoresis (CE) for semi-permanent coating of fused silica capillaries. The stability of the phospholipid coating was tested at different cetyltrimethylammonium bromide (CTAB) concentrations with and without CaCl(2) present in the coating solution. The effect of physical factors influencing the coating stability (e.

Nonaqueous capillary electrophoretic separation of polyphenolic compounds in wine using coated capillaries at high pH in methanol.

Nonaqueous capillary electrophoretic separation of a group of flavonoids (quercetin, myricetin, catechin, epicatechin) and resveratrol in wine was investigated in methanol at high pH. Malonate background electrolyte (pH* 13.5, ionic strength I = 14.

Heteroconjugation-based capillary electrophoretic separation of phenolic compounds in acetonitrile and propylene carbonate.

A mixture of methyl- and hydroxy-substituted phenols was separated by capillary electrophoresis in pure acetonitrile and propylene carbonate. Interactions between undissociated phenolic compounds and the background electrolytes were investigated. In the present work, benzyltriethylammonium chloride, tetrabutylammonium acetate, and two room temperature-molten salts, 1-butyl-3-methyl imidazolium trifluoroacetate and 1-butyl-3-methyl imidazolium heptafluorobutanoate, were used as background electrolytes.

Capillary electrophoresis of methyl-substituted phenols in acetonitrile.

The separation of mono- and dimethylphenols by capillary electrophoresis in pure acetonitrile was investigated. In acetonitrile, uncharged phenols interact with background electrolyte anions forming negatively charged complexes, which can be separated from each other by capillary electrophoresis. The background electrolyte anions tested were acetate, bromide and chloride.