We report on the application of sweeping-MEKC, for the first time, using the Environmental Protection Agency Method 8330 stock standard (a mixture of 14 explosives). The use of a traditional MEKC mode provided the LODs (at S/N=3) ranging from 1.5 to 2.9 microg/mL for the 14 explosives standards, which were improved by as low as 3.1-6.5 ng/mL when a sweeping-MEKC technique was used. A set of 21 ...

The aim of the present study was to examine the effect of micellar systems on the absorption of beta-lapachone (b-lap) through different intestinal segments using a single-pass rat intestinal perfusion technique. B-lap was solubilized in mixed micelles composed of phosphatidylcholine and sodium deoxycholate, and in sodium lauryl sulfate (SLS)-based conventional micelles. Both mixed micelles and...

Micellar electrokinetic chromatography (MEKC) has been applied for the determination of 5-hydroxymethylfurfural in several foodstuffs. A 75mM phosphate buffer solution at pH 8.0 containing 100mM sodium dodecylsulphate was used as background electrolyte (BGE), and the separation was performed by applying +25kV in a 50μm I.D. uncoated fused-silica capillary. Good linearity over the range 2.5-250m...

The optical properties (absorption and fluorescence) of fluorescein sodium were investigated with changing the bulk pH value in aqueous, water-methanol mixed and dodecylammonium propionate reversed micellar solutions. A strong buffer action was found in the reversed micellar solutions. The pK a values for the equilibrium between fluorescein monoand di-anions in the ground and excited singlet st...

Poly(L-lactic acid) is a linear aliphatic thermoplastic polyester that can be produced from renewable resources. A poly(L-lactic acid)-modified silica stationary phase was newly prepared by amide bond reaction between amino groups on aminopropyl silica and carboxylic acid groups at the end of the poly(L-lactic acid) chain. The poly(L-lactic acid)-silica column was characterized in reversed-phas...

Internet Electronic Conference of Molecular Design 2003, November 23 – December 6 Abstract Motivation. Biopartitioning micellar chromatography (BMC) is a mode of reversed phase micellar liquid chromatography that has proved to be useful in the description and prediction of several pharmacological properties of xenobiotics including oral drug absorption, ocular and skin drug permeability. The pr...

background ziziphora tenuior l. known as kakuti in persian, is used in traditional medicine for fever, dysentery, uterus infection and as an analgesic. it is used also in the treatment of gastrointestinal disorders as carminative, or remedy of diarrhea or nausea. major components of plant essential oil including pulegone, isomenthone, thymol, menthone, and piperitone are suggested to be respons...

background aflatoxins are one of the most potent toxic substances that occur naturally. nowadays extensive attention has been taken to their existence in food and environment, as there is the possibility of harm to humans following chronic exposure to extremely low levels via food chain. aflatoxin m1 (afm1) is a hepatic carcinogenic metabolite found in the milk of lactating animals fed with con...

background valproic acid is widely used as an anticonvulsant and mood-stabilizing drug in the treatment of epilepsy. determination of serum valproic acid is required in epilepsy therapy for efficient control of seizures. objectives in the present study, the gas chromatography method was applied to determine serum valproic acid and resulting data were compared with those obtained by high perform...