Home About us Contact
|
Home About us Contact | ||
|
|
||
Zone Electrophoresis Method (zone + electrophoresis_method)
Kinds of Zone Electrophoresis Method Selected AbstractsQuantitative measurement of collagen methylation by capillary electrophoresisELECTROPHORESIS, Issue 20 2004Jing Zhang Abstract Collagen methylation has been exploited in various applications involving living cells. We have observed correlation between the collagen methylation with the rate of cell proliferation in three-dimensional (3-D) microenvironment. To quantify the degree of collagen methylation, we have developed a capillary zone electrophoresis method. Using a polyvinyl alcohol-coated fused-silica capillary and UV detection at 200 nm, we have optimized pH and separated the native collagen into three major bands in phosphate buffer (50 mM, pH 2.5) with 0.05% hydroxypropylmethylcellulose. Under these conditions, the methylated collagens were separated into four major bands, which changed with different methylation reaction conditions. We propose an index to quantify the degree of collagen methylation that also correlates with their effects on cell proliferation. [source] Quantitation of talinolol and other ,-blockers by capillary electrophoresis for in vitro drug absorption studiesELECTROPHORESIS, Issue 15 2003Bilal Awadallah Abstract A capillary zone electrophoresis method is described for the enantioseparation of talinolol using heptakis(2,3-diacetyl-6-sulfo)-,-cyclodextrin (HDAS-,-CD) as a chiral selector. After liquid-liquid extraction of talinolol from physiological solution, electrokinetic injection was employed to improve the sensitivity. The use of a coated capillary was necessary to achieve stable and reproducible enantioseparations. A baseline separation of the talinolol enantiomers was achieved in less than 10 min using 100 mM phosphate solution as background electrolyte and pH 3.5, at the presence of 3.0 mM HDAS-,-CD and at 20°C. In addition, this analytical condition proved to be useful for the enantioseparation of a number of other ,-blocking agents such as alprenolol, atenolol, bisoprolol, celiprolol, metipranolol, oxprenolol, and sotalol. For determing talinolol, the method could be validated in terms of precision, accuracy and linearity, and was found to be suitable in determination of talinolol enantiomers in highly diluted samples obtained from in vitro experiments. [source] Analysis of alkaloids in Ipecacuanhae radix and preparations by capillary zone electrophoresisJOURNAL OF SEPARATION SCIENCE, JSS, Issue 12-13 2003Sonja Sturm Abstract A capillary zone electrophoresis method for quantitation of the alkaloids emetine and cephaeline in Ipecacuanhae radix fluid extract and Ipecac syrup using papaverine as internal standard is described. Baseline separation was achieved within 10 min using a fused silica capillary and a running electrolyte consisting of citric acid (50 mM), disodium hydrogenphosphate (100 mM), and 2.5% methanol (pH 4.4). Regression equations revealed a linear response from 0.05 to 1.9 mg/mL for cephaeline and emetine (correlation coefficients 0.9991,0.9993). The lowest quantitation limits were determined as 0.03 mg/mL for both alkaloids, and the limit of detection was 0.012 mg/mL. The day-to-day variations of retention times were < 1.3% for both compounds. Whereas no sample pre-treatment was necessary for analysis of the fluid extract, SPE had to be applied before CE analysis of the syrup. The recovery rate for emetine in this case was > 99.8%. [source] A capillary zone electrophoresis method for the quantitative determination of hypoxoside in commercial formulations of african potato (Hypoxis hemerocallidea)PHYTOCHEMICAL ANALYSIS, Issue 6 2007Vipin D. P. Nair Abstract Hypoxoside is a norlignan diglucoside present in the corms of African potato, Hypoxis hemerocallidea, used as a popular African traditional medicine for its nutritional and immune boosting properties. A specific analytical method employing capillary zone electrophoresis has been developed and validated for the quantitative determination of this analyte. Sulfafurazole was used as internal standard, and electrophoretic separation of both analytes could be achieved within 12 min. Linearity of the method was established within the range 5,60 µg/mL and provided a high degree of accuracy (100 ± 3%). The recovery of the method was found to be 100 ± 5% and the RSDs of the intra- and inter-day precision were better than 5.19 and 2.52%, respectively. The limits of detection and quantification were calculated to be 0.5 and 2 µg/mL, respectively. The described method was used for the analysis and quality control of two commercially available products containing African potato. The method can also be used to determine product stability since it could separate the hypoxoside peak from its degraded products obtained from degradation studies. Copyright © 2007 John Wiley & Sons, Ltd. [source] Rapid analysis of tetracaine for a tape stripping pharmacokinetic study using short-end capillary electrophoresisBIOMEDICAL CHROMATOGRAPHY, Issue 5 2009F. Al-Otaibi Abstract A rapid and simple short-end (reverse) capillary zone electrophoresis method was developed and validated for the separation and quantification of tetracaine in skin using tape samples. The separation was performed in a 485 mm (400 mm to window) × 50 µm internal diameter fused silica capillary using a background electrolyte of phosphoric acid,Tris pH2.5 at ,25 kV. The extraction of tetracaine from tape samples was achieved using methanol diluted to 50% with water before injection. Procaine was the internal standard. The migration times for procaine and tetracaine were 1.25 and 1.36 min, respectively. The limit of quantification for tetracaine was 50 µg, with a signal-to-noise ratio greater than 10. The calibration curve was linear from 50 to 1200 µg with r2 greater than 0.99. The CV for both within- and between-assay imprecision and the percentage inaccuracy for the quality control samples including lower and upper limits of quantitation were <12.1% and <11%, respectively. The absolute mean recovery of tetracaine was >97%. The accuracy and selectivity of this method allowed the rapid measurement of tetracaine in tape samples obtained from a skin tape stripping study of local anaesthetics in healthy subjects. Copyright © 2008 John Wiley & Sons, Ltd. [source] Determination of trimebutine maleate in rat plasma and tissues by using capillary zone electrophoresisBIOMEDICAL CHROMATOGRAPHY, Issue 4 2001Famei Li A simple and rapid capillary zone electrophoresis method was developed for the determination of trimebutine maleate in rat plasma and tissues. Rat plasma and tissue homogenates were mixed with acetonitrile containing internal standard, ephedrine hydrochloride, and then centrifuged. The supernatant was dried under a stream of nitrogen, and the residue was reconstituted in methanol,water (1:1). The electrophoresis was performed in uncoated capillary with 30,mmol/L phosphate buffer of pH 6.0 as the separation electrolyte. The applied voltage was 10,kV and the UV detection was set at 214,nm. The peak height ratio vs concentration in plasma or homogenates was linear over the range of 5,500,ng/mL and the limit of quantitation was 5,ng/mL. The intra- and inter-day precision was RSD,<,14% and <15%. The accuracy was relative error (RE) within,±,14%. This method was applied to studying the pharmacokinetics and tissue distribution after a single dose of trimebutine maleate was administrated to the rats. The Tmax, AUC, Cmax and t1/2 were 30,min, 7.8,×,102 (ng/mL),min, 39,ng/mL and 1.7,×,102,min. The drug distribution was found in a decreasing order of liver, kidney, spleen, lung and heart. Copyright © 2001 John Wiley & Sons, Ltd. [source] Synthesis of chiral vicinal diols and analysis of them by capillary zone electrophoresisCHIRALITY, Issue 2 2008Peng Liu Abstract This paper describes an improved access to 1,4-bis (9- O -quininyl) phthalazine [(QN)2PHAL], a very useful chiral ligand for catalytic asymmetric dihydroxylation (AD), by using CaH2 as acid-binding reagent in a high yield under mild conditions. The application of (QN)2PHAL to the AD reactions of eight olefins exhibited excellent enantioselectivity and activity with corresponding chiral vicinal diols. Furthermore, a capillary zone electrophoresis method was developed to separate the aforementioned chiral vicinal diols by using of neutral ,-cyclodextrin (,-CD) as chiral selector and borate as running buffer. High resolution was achieved under the optimal conditions of ,-CD 2.2% (w/v), pH 10, 200 mM borate buffer at 15 kV, and 20°C within 15 min. The relative standard deviations of the corrected peak areas and migration time were less than 3.9% and 1.3%, respectively. In addition, the developed method was successfully applied to the determination of the purity and the enantiomeric excesses value (%ee) of the AD reaction products. Chirality, 2008. © 2007 Wiley-Liss, Inc. [source] | ||||||||||