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Separation
Kinds of Separation Terms modified by Separation Selected AbstractsECONOMIC GROWTH AND THE SEPARATION OF CHURCH AND STATE: THE FRENCH CASEECONOMIC INQUIRY, Issue 4 2010RAPHAËL FRANCK This article provides a test of the secularization hypothesis, which argues that economic growth, industrialization, increased literacy, and low fertility decrease religiosity. It focuses on the elections of the secular politicians who voted in favor of the separation between Church and State in the French Parliament in 1905. If the secularization hypothesis is correct, these secular politicians should have been elected in the most developed areas of France at the turn of the twentieth century. Contrary to the predictions of the secularization hypothesis, we find that the support for secular politicians originated in the rural areas of France. (JEL Z12, D72, N43) [source] GUEST EDITORS' INTRODUCTION TO SPECIAL ISSUE ON ALIENATED CHILDREN IN DIVORCE AND SEPARATION: EMERGING APPROACHES FOR FAMILIES AND COURTSFAMILY COURT REVIEW, Issue 1 2010Barbara Jo Fidler First page of article [source] CHILDREN'S AND PARENTS' PERCEPTIONS ON CHILDREN'S PARTICIPATION IN DECISION MAKING AFTER PARENTAL SEPARATION AND DIVORCE*FAMILY COURT REVIEW, Issue 1 2008Judy Cashmore This article outlines the views of children and parents involved in family law disputes, about the need for and appropriateness of children's participation in decisions regarding residence and contact arrangements. Ninety parents and 47 children (ranging in age from 6 to 18 years) who had been through parental separation, were interviewed. Both parents and children had a range of views about the general appropriateness and fairness of children being involved, but the great majority, particularly of parents, thought that children should have a say in these matters. Core findings of the study include the considerable influence that older children had over the arrangements either in the aftermath of the separation or in making further changes over time, and the higher stated need of children who had experienced violence, abuse, or high levels of conflict to be heard than those in less problematic and noncontested matters. Parents involved in contested proceedings supported the participation of children at a younger age than those who were not. There was a reasonable degree of agreement between parents and children about the need for children to be acknowledged and the value of their views being heard in the decision-making process. Parents, however, expressed concern about the pressure and manipulation that children can face and exert in this process, whereas children were generally more concerned about the fairness of the outcomes, and maintaining their relationships with their parents and siblings. [source] APPLICATION OF COEFFICIENT OF FRICTION TO THE SEPARATION OF COCOA HUSK,BEANS MIXTUREJOURNAL OF FOOD PROCESS ENGINEERING, Issue 5 2007O.K. OWOLARAFE ABSTRACT Investigation was carried out on the application of coefficient of friction in the separation of cocoa beans,husk mixture. An inclined plane at angles 20, 25 and 35°rotating at different speeds (215, 250 and 260 rpm) and receiving the mixture at heights 30, 60 and 90 mm, was used for the study. The result indicates that within the range of factors considered, the separation efficiency of the beans from the mixture increases with increase in speed of rotation and height of fall, while it decreases with increase in angle of inclination. Statistical analysis shows that the effects of each of the factors and that of their interaction are significant at 99%. The best separation efficiency (99%) was observed at a speed of 250 rpm, an angle of inclination of 25° and a height fall of 90 mm. PRACTICAL APPLICATIONS Separation of cocoa beans from the husks has been a serious problem in cocoa processing. Handpicking is still being used to separate the mixture of cocoa beans,husk even with the mechanical pod breaker available. This therefore constitutes a tedious operation. An inclined plane mechanism tested for the separation of the mixture in this study can be incorporated into the design of the cocoa pod processor to reduce the drudgery involved in cocoa processing and improve the quality of the product. [source] CHROMATOGRAPHIC SEPARATION AT A PREPARATIVE SCALE OF EGG WHITE OVALBUMIN AND ITS APPLICATION IN THE ELABORATION OF YOGURT MOUSSEJOURNAL OF FOOD PROCESS ENGINEERING, Issue 1 2006B. PAREDES ABSTRACT Egg white contains high-quality proteins. Some processes using eggs produce egg white as by-product. These egg white proteins may be recovered for use as additive in food products. In the first part of this study, a new polymeric material was developed and used in the chromatographic separation of ovalbumin at preparative scale. Ovalbumin is the major component of egg white and thus, it has the greatest weight in terms of its functional effects. An application of the purified ovalbumin was subsequently studied in the elaboration of yogurt mousse. The results obtained showed that the poly(glycidil methacrylate-co-ethylene dimethacrylate) resin that was manufactured enabled the separation of ovalbumin with good efficiency. This study also showed that the formulation obtained from the yogurt mousse with ovalbumin had a greater yield in volume than the commercial product used as a benchmark, improving the majority of its organoleptic qualities without appreciably affecting its stability and organoleptic properties. [source] RHEOLOGICAL PROPERTIES, WHEY SEPARATION, AND MICROSTRUCTURE IN SET-STYLE YOGURT: EFFECTS OF HEATING TEMPERATURE AND INCUBATION TEMPERATUREJOURNAL OF TEXTURE STUDIES, Issue 5-6 2003WON-JAE LEE The effects of heat treatment and incubation temperature on the rheological and microstructural properties of yogurt were studied. A central composite experimental design and response surface methodology were used for data analysis. The rheological properties were determined by dynamic low amplitude oscillation and the amount of spontaneous whey separation was quantified by the volumetric flask test. Confocal scanning laser microscopy was used to examine the gel structure. The storage moduli of yogurts increased with an increase in heating temperature and a decrease in incubation temperature. The maximum loss tangent value during gelation, permeability, and amount of spontaneous whey separation of yogurts increased with a decrease in heating temperature and with an increase in incubation temperature. These parameters indicated an increased possibility for rearrangements, which was confirmed by presence of large pores in the gel network. Second order polynomial models successfully predicted the effects of heating temperature and incubation temperature on the rheological properties, permeability, and whey separation of yogurts. Whey separation was negatively correlated with storage modulus (r= -0.66), and was positively correlated with the maximum loss tangent (r= 0.63) and permeability (r= 0.78). This study demonstrates that weak yogurt gels, which have high loss tangent values, favor rearrangements in the network and the resulting network has larger pores (high permeability) and exhibits greater whey separation. [source] PHYSIOLOGICAL AND BEHAVIORAL DEVELOPMENT IN DELPHINID CALVES: IMPLICATIONS FOR CALF SEPARATION AND MORTALITY DUE TO TUNA PURSE-SEINE SETSMARINE MAMMAL SCIENCE, Issue 1 2007Shawn R. Noren Abstract Tuna purse-seiners in the eastern tropical Pacific (ETP) capture yellowfin tuna by chasing and encircling herds of associated dolphins. This fishery has caused mortality in 14 dolphin species (20 stocks) and has led to significant depletions of at least three stocks. Although observed dolphin mortality is currently low, set frequency remains high and dolphin stocks are not recovering at expected rates. Mortality of nursing calves permanently separated from their mothers during fishery operations may be an important factor in the lack of population recovery, based on the recent discovery that calves do not accompany 75%,95% of lactating females killed in the purse-seine nets. We assessed age-specific potential for mother,calf separations and subsequent mortality of calves by reviewing and synthesizing published data on physiological and behavioral development in delphinids from birth through 3 yr postpartum. Results indicate that evasive behavior of mothers, coupled with the developmental state of calves, provides a plausible mechanism for set-related mother,calf separations and subsequent mortality of calves. Potential for set-related separation and subsequent mortality is highest for 0,12-mo-old dolphins and becomes progressively lower with age as immature dolphins approach adult stamina and attain independence. [source] Separation, domestic violence, and divorce mediationCONFLICT RESOLUTION QUARTERLY, Issue 4 2006Desmond Ellis DOVE, an instrument designed to assess and manage the risk of domestic violence, was administered to a sequential, random sample of one hundred forty-seven male and female partners prior to their participation in divorce mediation. Nineteen statistically significant predictors of both pre- and post-separation violence and abuse were identified. Conjugal violence and abuse, male partner control, and mental health problems were prominent among predictors of post-separation violence and abuse. Safety plan interventions and referrals aimed at promoting women's safety during and following their participation in divorce mediation are identified in the concluding segment of the paper. [source] The braincase of the chondrichthyan Doliodus from the Lower Devonian Campbellton Formation of New Brunswick, CanadaACTA ZOOLOGICA, Issue 2009John Maisey Abstract The braincase of the late Lower Devonian (Emsian) chondrichthyan Doliodus is described for the first time. Its postorbital process is extended ventrally and probably enclosed part of the infraorbital sensory canal, as in some placoderms. Doliodus has a shark-like dentition, but its upper anterior tooth files were supported by the internasal cartilage of the braincase, not by the palatoquadrates. Modern selachian jaws and dentitions are not representative of primitive crown-group gnathostomes because they display a mixture of conserved and derived character states. Separation of the palatoquadrates by the internasal cartilage is probably a primitive condition for crown-group gnathostomes. Continuity of the upper dental arcade across the ethmoid region may represent a synapomorphy of chondrichthyans and some acanthodians (the condition is not found in placoderms or osteichthyans). Exclusion of the arcade from the ethmoid region is probably apomorphic within elasmobranchs. Doliodus has curious bar-like, paired subcranial ridges ending posteriorly at the hyomandibular articulation. These superficially resemble visceral arch infrapharyngohyals fused to the floor of the braincase, adding circumstantial palaeontological support to the old proposal that parts of visceral arches may be incorporated into the gnathostome braincase, although it seems more plausible that they formed in the lateral margins of the embryonic parachordal or hypotic lamina. [source] Cell organization of barb ridges in regenerating feathers of the quail: implications of the elongation of barb ridges for the evolution and diversification of feathersACTA ZOOLOGICA, Issue 2 2007L. Alibardi Abstract This ultrastructural study on the regenerating feathers of quail describes the cellular organization of the barb ridges responsible for the ramification of adult feathers. Bilateral symmetry of the barb ridges determines the organization of feather cells into feather branching. The length of the barb ridges, derived from the number of cells associated to form the barbule plates, determines the length of the barbule branching. Long chains of barb cells form long barbs that branch from the rachis with an increase of feather size. Supportive cells function as spacers between the barbule cells. New cells derive from stem cells localized in the collar region of the feather follicle, as indicated from the re-organization of collar cells into barb ridges (a morphogenetic process inherited from that of embryonic feathers), production of an embryonic type of keratin (feather keratin), permanence of periderm granules (typical embryonic organelles) in barb vane ridge cells. Variations in the process of barb ridge morphogenesis allow the fusion of ridges into a rachis. The differentiation of hooklets contributes to the origin of planar feathers. Separation between rachis and merging barb ridges is by supportive cells, derived from the marginal plates of the barb ridges. Speculations on the evolution and diversification of feathers are presented. [source] Quantification of Annular Dilatation and Papillary Muscle Separation in Functional Mitral Regurgitation: Role of Anterior Mitral Leaflet Length as ReferenceECHOCARDIOGRAPHY, Issue 6 2005Vinod Jorapur M.D. Background: We hypothesized that anterior mitral leaflet length (ALL) does not differ significantly between normal subjects and patients with functional mitral regurgitation (FMR) and hence may be used as a reference measurement to quantify annular dilatation and papillary muscle separation. Methods and Results: We prospectively studied 50 controls, 15 patients with systolic left ventricular dysfunction (LVD) with significant FMR, and 15 patients with LVD without significant FMR. Significant MR was defined as an effective regurgitant orifice area , 0.2 cm2 as measured by the flow convergence method. Annular diameter, interpapillary distance, and ALL were measured, and the following ratios were derived: annular diameter indexed to ALL (ADI) and interpapillary distance indexed to ALL (IPDI). There was no significant difference in ALL among the three groups. The mean ADI was 1.26 times controls in patients with LVD without significant FMR compared to 1.33 times controls in patients with LVD with significant FMR (P = 0.06, no significant difference between groups). The mean IPDI was 1.42 times controls in patients with LVD without significant FMR compared to 2.1 times controls in patients with LVD with significant FMR (P < 0.0001, significant difference between groups). Conclusion: There was no significant difference in ALL between controls and patients with LVD. ALL can be used as a reference measurement to quantify annular dilatation and papillary muscle separation in patients with FMR. Interpapillary distance but not annular diameter indexed to ALL correlates with severity of FMR. [source] Parental Separation and Children's Educational Attainment: A Siblings Analysis on Swedish Register DataECONOMICA, Issue 292 2006ANDERS BJÖRKLUND This paper analyses whether the commonly found negative relationship between parental separation in childhood and educational outcomes is causal or due mainly to selection. We use data on about 100,000 Swedish full biological siblings, born in 1948,63, and perform cross-section and sibling-difference estimations. Outcomes are measured as educational attainment in 1996. Our cross-section analysis shows the expected negative and significant relationship, while the relationship is not significant, though precisely estimated, in the sibling-difference analysis. This finding was robust to the sensitivity tests performed and is consistent with selection, rather than causation, being the explanation for the negative relationship. [source] Separation and Detection of Narcotic Drugs on a Microchip Using Micellar Electrokinetic Chromatography and ElectrochemiluminescenceELECTROANALYSIS, Issue 6 2008Yan Du Abstract A new approach for fast and sensitive electrochemiluminescence (ECL) detection of narcotic drugs on a microchip after separation by micellar electrokinetic chromatography (MEKC) is presented, taking the cocaine and its hydrolysate ecgonine as the test analytes. The mixture of hydrophilic BMIMBF4 ionic liquid (IL) and sodium dodecyl sulfate (SDS) was used directly as the buffer of MEKC with less noisy baselines, lower electrophoretic current and satisfactory separation performance. This developed microchip MEKC,ECL system was successfully applied to the determination of two very similar narcotics, heroin and codeine, within 100s in urine sample and was demonstrated as a promising method in clinical and forensic analysis. [source] Separation and Detection of Nitrophenols at Capillary Electrophoresis Microchips with Amperometric DetectionELECTROANALYSIS, Issue 2 2006Jan Fischer Abstract A miniaturized analytical system for the separation and amperometric detection of toxic nitrophenols, based on the coupling of a micromachined capillary electrophoresis (CE) chip with a glassy carbon detector is described. This microsystem enables a rapid (120,s/sample) simultaneous determination of five priority nitrophenolic pollutants (2-nitrophenol, 3-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol, and 2-methyl-4,6-dinitrophenol). These compounds can be detected down to the 1×10,5,M level using a 15,mM phosphate buffer pH,7.2 (containing 1.3,mM ,-cyclodextrin) as running solution on 77,mm long microchannel by applying a separation voltage of 3000,V and a negative potential of ,0.7,V (vs. Ag /AgCl wire). Applicability to ground water samples was demonstrated. [source] Lectin-aided separation of circulating tumor cells and assay of their response to an anticancer drug in an integrated microfluidic deviceELECTROPHORESIS, Issue 18 2010Li Li Abstract Metastasis caused by the entry of circulating tumor cells (CTCs) into the bloodstream or lymphatic vessels is a major factor contributing to death in cancer patients. Separation of CTCs and studies on CTC,drug interactions are very important for prognostic and therapeutic implications of metastatic cancer. In this study, an integrated microfluidic device for CTC separation through the combination of lectin and microstructure is presented. This microfluidic device and lectin concanavalin A were utilized for the separation of K562 cells in whole blood samples. The results showed that the separation efficiency can reach 84%, which is much higher than that of an experiment without concanavalin A treatment. To further demonstrate the feasibility of this microfluidic device application in sequential studies after target cells were separated, the interactions of K562 cells and an anticancer drug, cytarabine, were also examined. After 6,h on-chip treatment with cytarabine, the viabilities of K562 cells were 85.29, 77.05, and 40% for drug concentration levels of 0.25, 0.5, and 1.0,g/L, respectively. This system can facilitate the rapid and efficient in vitro investigation of CTC separation and CTC-related studies. [source] Cover Picture: Electrophoresis 10'2010ELECTROPHORESIS, Issue 10 2010Article first published online: 18 MAY 2010 Issue no. 10 is a regular issue comprising 19 manuscripts distributed over four distinct parts. Part I is on microfluidics and miniaturized systems and has 5 articles; Part II is on nucleic acids with 4 articles on restriction endonuclease fingerprinting, mutation detection and DNA separation and detection; Part III has 7 articles on monolithic stationary phases for CEC, single walled carbon nanohorns as pseudo-stationary phases for CEC and EKC, MEEKC, cyclodextrin-modified gold nanoparticles for enantioseparations by CEC, use of divalent dipeptides as counter ions in CE and capillary coating for CE of proteins; and Part IV has 3 articles on proteomics methodologies. Featured articles include: Microfluidic preparative free-flow isoelectric focusing in a triangular channel: System development and characterization ((10.1002/elps.200900577)) Separation and recovery of nucleic acids with improved biological activity by acid-degradable polyacrylamide gel electrophoresis ((10.1002/elps.200900783)) Evaluation of the performance of single-walled carbon nanohorns in capillary electrophoresis ((10.1002/elps.200900628)) The inter- and intra-operator variability in manual spot segmentation and its effect on spot quantitation in two dimensional electrophoresis analysis. ((10.1002/elps.200900674)) [source] Separation of amino alcohols using divalent dipeptides as counter ions in aqueous CEELECTROPHORESIS, Issue 10 2010Jakob Haglöf Abstract Divalent dipeptides have been introduced as counter ions in aqueous CZE. The dipeptides form ion pairs with amino alcohols in the BGE and facilitate the separation of amino alcohols. High concentrations of dipeptide caused reversed effective mobility for the analytes. The net charge of the dipeptide can be controlled using a buffer or a strong base, and regulates the interaction between the dipeptide and the amino alcohol. A stronger interaction and higher selectivity of amino alcohols was observed when the dipeptides were used as divalent counter ions, than in monovalent or uncharged form. Association constants for ion pairs between divalent dipeptides and amino alcohols can be used to enhance selectivity for amino alcohols in CZE. No chiral separation of amino alcohols was observed when using the dipeptides as ion-pairing chiral selectors in aqueous BGE, but addition of methanol to the BGE promoted enantioselectivity. [source] Separation of propranolol enantiomers by CE using sulfated ,-CD derivatives in aqueous and non-aqueous electrolytes: Comparative CE and NMR study,ELECTROPHORESIS, Issue 9 2010Anne-Catherine Servais Abstract Separations using CE employing non-aqueous BGE are already as well established as separations in aqueous buffers. The separation mechanisms in achiral CE with non-aqueous BGEs are most likely similar to those in aqueous buffers. However, for the separation of enantiomers involving their interaction with chiral buffer additives, the interaction mechanisms might be very different in aqueous and non-aqueous BGEs. While the hypothesis regarding distinct mechanisms of enantiomer separations in aqueous and non-aqueous BGEs has been mentioned in several papers, no direct proof of this hypothesis has been reported to date. In the present study, the enantiomers of propranolol were resolved using CE in aqueous and non-aqueous methanolic BGEs with two single isomer sulfated derivatives of ,-CD, namely heptakis (2,3-diacetyl-6-sulfo)-,-CD and heptakis (2,3-dimethyl-6-sulfo)-,-CD. The enantiomer migration order of propranolol was inverted when an aqueous BGE was replaced with non-aqueous BGE in the case of heptakis (2,3-dimethyl-6-sulfo)-,-CD but remained the same in the case of heptakis (2,3-diacetyl-6-sulfo)-,-CD. The possible molecular mechanisms leading to this reversal of enantiomer migration order were studied by using nuclear overhauser effect spectroscopy in both aqueous and non-aqueous BGEs. [source] Cover Picture: Electrophoresis 8'2010ELECTROPHORESIS, Issue 8 2010Article first published online: 20 APR 2010 Issue no. 8 is a regular issue comprising19 manuscripts distributed over four distinct parts. Part I is on proteins and proteomics and has 5 articles; Part II is on nucleic acids with 5 articles on DNA purification, sequencing, genotyping and differential gene expression; Part III has 4 articles on droplet dispensing and particle separation; Part IV is on various methodologies and applications assembling 5 articles on improved sample preparation method for glycan analysis by CE, measurement of intracellular accumulation chemotherapeutic drugs in cancerous cells, metabolic monitoring in microfluidic cell arrays, microchip electrophoresis for continuous monitoring of microdialysis samples, and determination of glyphosate and its metabolites in plant materials by CE. Featured articles include: Delta2D and Proteomweaver: Performance evaluation of two different approaches for two-dimensional electrophoresis analysis. ((10.1002/elps.200900766)) A Multidimensional Electrophoretic System of Separation for the Analysis of Gene Expression (MESSAGE). ((10.1002/elps.200900624)) Particle trapping using dielectrophoretically patterned carbon nanotubes. ((10.1002/elps.200900717)) [source] Cover Picture: Electrophoresis 5'2010ELECTROPHORESIS, Issue 5 2010Article first published online: 26 FEB 2010 Issue no. 5 is a Special issue on "Fundamentals of Electrophoresis". Part I has 5 review articles on the various fields of electrophoresis. Separation in nano-channels is treated in 3 articles in Part II. Part III has 3 research papers on computer simulation of electromigration and Part IV also has 3 articles on stacking and focusing. Interaction in electrophoretic systems is the subject of Part V which has 6 research papers. Finally, electroosmotic flow is described in 1 paper in part VI. [source] Separation of peptides by open-tubular capillary electrochromatography using Fe(III)-deuteroporphyrin as a covalently attached stationary phaseELECTROPHORESIS, Issue 13 2009Ángel Yone Abstract The separation of seven biologically active peptides was attempted by open-tubular capillary electrochromatography in fused-silica capillaries chemically modified with iron (III)-deuteroporphyrin using UV-absorption detection at 214,nm. The effect of BGE pH and content of organic solvent modifier was investigated. The best separations were obtained in 25,mM phosphate (BGE), pH 4.0, containing 5%,v/v ACN and 10,mM hydroquinone, which was added to prevent gas bubble formation. Considering the method sensitivity, lower concentration LODs were obtained for all peptides in their open-tubular capillary electrochromatography separation as compared with their CZE separation in bare fused-silica capillary. The iron (III)-deuteroporphyrin column proved to be highly stable over time and showed acceptable precision of migration times and corrected peak areas (RSD in the range 2,4%). [source] Separation of enantiomers with charged chiral selectors in CEELECTROPHORESIS, Issue S1 2009Bezhan Chankvetadze Abstract In this short overview the major developments in separation of enantiomers with charged chiral selectors are summarized in CE. The advantages of charged chiral selectors in comparison with their uncharged analogues are emphasized from the viewpoints of higher flexibility, higher and alternative separation selectivity, as well as alternative chiral recognition mechanism. [source] Separation of multiphosphorylated peptide isomers by CZEELECTROPHORESIS, Issue 21 2008Marika V. Muetzelburg Abstract A separation of mono, doubly and triply phosphorylated isomers was developed with CZE with an aqueous electrolyte containing 3.9,mol/L formic acid and 30%,v/v trifluoroethanol. Thus a mixture of ten phosphopeptides corresponding to the human tau sequence 226,240 was separated within 70,min. Although peptides with different phosphorylation degrees, i.e. 0,3 phosphate groups, were well separated, some of the phosphopeptide isomers containing one or two phosphate groups were only partially separated. The electrolyte system is compatible with both MALDI- and ESI-MS, allowing a direct coupling, and thus could have some interesting applications in proteomics. [source] Chiral separation of the plant lignan matairesinol by capillary electrophoresis,ELECTROPHORESIS, Issue 17 2008Ulrike Müller Abstract Lignans are dimeric phenylpropanoid compounds in plants that enjoy increasing medicinal interest because of their phytoestrogen activity. Lignans are chiral compounds and for most natural occurring lignans, chirality is not known. Separation of racemic matairesinol by CE in a non-coated silica capillary with carboxymethyl-,-cyclodextrin as chiral selector in phosphate buffer was successful. Electrolyte and selector concentrations and pH were systematically optimized in order to obtain baseline separation and short analysis times. Matairesinol from safflower fruit was determined as (,)-enantiomer. Quantitation results for matairesinol with the optimized method after calibration with authentic lignan were very similar to those by HPLC. The limit of detection is 2,,g/mL sample by DAD detection. [source] A simple and rapid CZE method for the analysis of mycophenolic acid and its phenol glucuronide metabolite in human serum,ELECTROPHORESIS, Issue 17 2008Kaname Ohyama Abstract A simple and rapid capillary electrophoretic method was developed for simultaneous determination of mycophenolic acid and its metabolite, phenol glucuronide, in human serum. The sample preparation in the proposed method required only the precipitation by acetonitrile. Separation was performed by capillary zone electrophoresis using 75,mM phosphate buffer (pH 7.5) as running buffer, an applied voltage of 10,kV, and UV detection at 217,nm. Each serum sample analysis was completed within 15,min. The optimized method demonstrated good performance concerning specificity, linearity (r>0.9955), accuracy (95.9,113%), precision (<6.4%) and enough sensitivity for therapeutic drug monitoring. This method was successfully applied to measurements of mycophenolic acid and mycophenolic acid glucuronide in renal transplant patient samples and was a useful alternative to high-performance liquid chromatography-based methods. [source] Separation of cytokinin isomers with a partial filling-micellar electrokinetic chromatography-mass spectrometry approachELECTROPHORESIS, Issue 10 2008Liya Ge Abstract A new method based on partial filling-MEKC (PF-MEKC) directly coupled to ESI-MS was developed for the simultaneous separation and determination of 13 structurally similar cytokinins, including various geometric and positional isomers of cytokinins. On the basis of the resolution of the neighboring isomer peaks, different parameters (i.e., pH and concentration of buffer, surfactant concentrations, length of the injected micellar plug, organic modifier, and applied separation voltage) were optimized to achieve a satisfactory PF-MEKC separation. Under optimum conditions, the separation of 13 cytokinin standards was accomplished within 25,min. MS/MS with multiple reaction monitoring detection was carried out to obtain sufficient selectivity. PF-MEKC-MS/MS allowed for the direct identification and confirmation of the cytokinins present in banana (Musa spp.) pulp sample after extraction and purification. Finally, trans- zeatin riboside (ZR) and trans- zeatin (Z) were unambiguously identified in banana pulp. It is anticipated that the current PF-MEKC-MS method can be applied to analyze cytokinins in a wide range of biological samples. [source] Determination of neutral carbohydrates by CZE with direct UV detectionELECTROPHORESIS, Issue 17 2007Stella Rovio Abstract A new CZE method relying on in-capillary reaction and direct UV detection at the wavelength 270,nm is presented for the simultaneous separation of the neutral carbohydrates xylitol, D -(,)-mannitol, sucrose, D -(+)-fucose, D -(+)-cellobiose, D -(+)-galactose, D -(+)-glucose, L -rhamnose, D -(+)-mannose, D -(,)-arabinose, D -(+)-xylose, and D -(,)-ribose. The alkaline electrolyte solution was prepared of 130,mM sodium hydroxide and 36,mM disodium hydrogen phosphate dihydrate. Separation of the sample mixture was achieved within 35,min. Calibration plots were linear in the range of 0.05,3,mM. Reproducibility of migration times was between 0.3 and 1.1%, and the detection limits for the analytes were 0.02 and 0.05,mM. The optimized method was applied for the determination of neutral monosaccharides in lemon, pineapple, and orange juices and a cognac sample. The methodology is fast since no other sample preparation except dilution is required. [source] Separation of Nile Blue-labelled fatty acids by CE with absorbance detection using a red light-emitting diodeELECTROPHORESIS, Issue 8 2007Michael C. Breadmore Dr. Abstract The separation of fatty acids derivatised with Nile Blue (NB) by CE with detection using a red light-emitting diode (LED) was examined. NB was selected as the derivatisation agent due to its high molar absorption coefficient of 76,000,M,1cm,1 at 633,nm, making it well suited for sensitive absorbance detection using a red 635,nm LED. NB-labelled fatty acids were separated by both MEKC using SDS micelles, i -PrOH and n -BuOH and by NACE in a number of solvents including MeOH, EtOH and ACN. The sensitivity of NACE was superior to MEKC, with detection limits of 5×10,7,7×10,7,M obtained for each acid, approximately 20 times lower than the MEKC method. The NACE detection limits are approximately 100 times lower than previous reports on the separation of fatty acids by CE using indirect absorbance detection, ten times lower than using indirect fluorescence detection and are inferior only to those obtained using precapillary derivatisation and direct fluorescence detection. The efficiency of the NACE method was also superior to MEKC and allowed the separation of unsaturated fatty acids to be examined, although it was not possible to baseline-resolve linoleic (C18:2) and linolenic (C18:3) acids in a reasonable time. The method was used to analyse the fatty acid profile of two edible oils, namely sunflower and sesame oils, after alkali hydrolysis, where it was possible to identify both the saturated and unsaturated fatty acids in each sample. [source] Effects of lactate and acetate on the determination of serum ethyl glucuronide by CZEELECTROPHORESIS, Issue 23 2006Michaela Mrázková Abstract The analysis of ethyl glucuronide,(EtG), a marker of recent alcohol consumption, in serum with an optimized CZE assay is reported. The method uses a 0.1-mm,id fused-silica capillary of 50,cm effective length that is coated with linear polyacrylamide, a pH,4.4 nicotinic acid/,-aminocaproic acid (EACA) BGE, reversed polarity and indirect analyte detection. The assay is based on a 1:1 dilution of serum with deionized water and has LODs for EtG, lactate and acetate of 3.8×10,7,M, 2.60×10,6,M and 2.18×10,6,M, respectively. Separation of EtG from endogenous macro- and microcomponents (anionic serum components of high and low concentration, respectively) and its quantification are shown to be possible for a wide range of lactate (stacker) and acetate (destacker) concentrations, macrocomponents that have an impact on the CZE behavior of EtG and that change after intake of ethanol. The assay has been successfully applied to the analysis of EtG, lactate and acetate in (i),sera of volunteers that ingested known amounts of alcohol and (ii),samples of patients that were classified (teetotalers and social drinkers vs. alcohol abusers) via analysis of carbohydrate-deficient transferrin. [source] Separation of nuclear protein complexes by blue native polyacrylamide gel electrophoresisELECTROPHORESIS, Issue 7 2006Zora Nováková Abstract The nucleus is a highly structured organelle with distinct compartmentalization of specific functions. To understand the functions of these nuclear compartments, detailed description of protein complexes which form these structures is of crucial importance. We explored therefore the potential of blue native PAGE (BN-PAGE) method for the separation of nuclear protein complexes. We focused on (i),solubility and stability of nuclear complexes under conditions prerequisite for the separation by BN-PAGE, (ii),improved separation of native nuclear protein complexes using 2-D colorless native/blue native PAGE (CN-/BN-PAGE), and (iii),mass spectrometric analysis of protein complexes which were isolated directly from native 1-D or from 2-D CN/BN-PAGE gels. The suitability of BN-PAGE for nuclear proteomic research is demonstrated by the successful separation of polymerase,I and polymerase,II complexes, and by mass spectrometric determination of U1 small nuclear ribonucleoprotein particle composition. Moreover, practical advice for sample preparation is provided. [source] | ||||||||||||||||||||||||||||||||||||||||||||||||||||