A cloud point extraction coupled with high performance liquid chromatography (HPLC/UV) method was developed for the determination of Δ(9)-tetrahydrocannabinol (THC) in micellar phase. The nonionic surfactant "Dowfax 20B102" was used to extract and pre-concentrate THC from cannabis resin, prior to its determination with a HPLC-UV system (diode array detector) with isocratic elution. The paramete...

This article refers to:Formation of Lyotropic Micellar Nematic Phase in Binary Mixture Liquid Crystals

The phase behavior and microstructure of aqueous mixtures of n-octyl-beta-D-glucoside (C8betaG1) and triethylene glycol mono-n-octyl ether (C8E3) is presented. C8betaG1 forms a one-phase micellar solution in water at surfactant concentrations up to 60 wt %, whereas mixtures with C8E3 show a liquid-liquid phase transition at low surfactant concentration. The position of this phase boundary for m...

We determined the distribution of lecithin molecular species between vesicles and mixed micelles in cholesterol super-saturated model biles (molar taurocholate-lecithin-cholesterol ratio 67:23:10, 3 g/dl, 0.15 M NaCl, pH approximately 6-7) that contained equimolar synthetic lecithin mixtures or egg yolk or soybean lecithins. After apparent equilibration (48 h), biles were fractionated by Supero...

Two methods, high-performance liquid chromatography (HPLC) and micellar electrokinetic chromatography (MEKC), for analysis of multicomponent lipopeptide antibiotic iturin A are described. After conducting a series of optimizations, the HPLC separation of iturin A2, A3, A4, A5, A6, A7, and A8 isomers were achieved by a NPS RP-C18 column with an isocratic elution of acetonitrile/10 mM ammonium ac...

A microwave-assisted fluorescence labeling method for use in CE-LIF (capillary electrophoresis-laser induced fluorescence) is described. Six amphetamine-like designer drugs, namely, o-, m-, p-chloro- and o-, m-, p-fluoro-amphetamine derivatives, were synthesized and used as model compounds. FITC (fluorescein isothiocyanate isomer I) and a blue-laser were used as the fluorescent labeling reagent...

The separation and on-line concentrations of lysergic acid diethylamide (LSD), iso-lysergic acid diethylamide (iso-LSD) and lysergic acid N,N-methylpropylamide (LAMPA) in human urine were investigated by capillary electrophoresis-fluorescence spectroscopy using sodium dodecyl sulfate (SDS) as an anionic surfactant. A number of parameters such as buffer pH, SDS concentration, Brij-30 concentrati...

short timeframe, and rapid approaches are needed to assess log Pow values of these compounds (2,4,7). Several separation-based approaches for indirectly determining log Pow values in a rapid fashion have been reported, including reversed-phase high performance liquid chromatography (HPLC) (2,3,8–11), thin-layer chromatography (12,13), micellar electrokinetic chromatography (MEKC) (7,14–16), and...

Although acute intoxication has become rare, arsenic (As) is still a dangerous pollution agent for industrial workers and people living in the vicinity of emission sources. In humans, only inorganic As is toxic; organic forms present in large amounts in the environment are nontoxic. It is therefore important to be able to differentiate one group from the other using appropriate speciation metho...