On-Column Ion-Exchange Preconcentration of Inorganic Anions in Open Tubular Capillary Electrochromatography with Elution Using Transient-Isotachophoretic Gradients. 3. Implementation and Method Development
TY - JOUR. T1 - Shielded stationary phases based on porous polymer monoliths for the capillary electrochromatography of highly basic biomolecules. AU - Hilder, Emily F.. AU - Svec, Frantisek. AU - Frechet, Jean. PY - 2004/7/15. Y1 - 2004/7/15. N2 - A novel stationary phase for capillary electrochromatography has been prepared via photoinitiated grafting of two layers of polymer chains onto the pore surface of a porous polymer monolith. To achieve the desired retention, the original monolith with optimized porous properties was grafted with an interior layer consisting of the ionizable monomer, 2-acrylamido-2-methyl-1-propanesulfonic acid, followed by a covering layer of hydrophobic polymer chains. This technique affords monolithic CEC columns that facilitate electroosmotic flow (EOF) while preventing ionized analytes from interacting with the charged surface functionalities. Grafting of the second layer does not adversely affect the EOF. Grafting times of 30 and 60 s for AMPS and butyl ...
This graph shows the total number of publications written about Capillary Electrochromatography by people in this website by year, and whether Capillary Electrochromatography was a major or minor topic of these publications ...
TY - JOUR. T1 - Polyethylenimine-modified metal oxides for fabrication of packed capillary columns for capillary electrochromatography and capillary liquid chromatography. AU - Wiedmer, Susanne K.. AU - DOrazio, Giovanni. AU - Smått, Jan-Henrik. AU - Bourdin, Delphine. AU - Baños-Pérez, Clara. AU - Sakeye, Motolani. AU - Kivilompolo, Maarit. AU - Kopperi, Matias. AU - Ruiz-Jiménez, José. AU - Fanali, Salvatore. AU - Riekkola, Marja-Liisa. PY - 2011. Y1 - 2011. U2 - 10.1016/j.chroma.2010.12.071. DO - 10.1016/j.chroma.2010.12.071. M3 - Artikel. VL - 1218. SP - 5020. EP - 5029. JO - Journal of Chromatography A. JF - Journal of Chromatography A. SN - 0021-9673. IS - 30. ER - ...
High-speed capillary electrochromatography was developed on both short and long packed columns with 2 mu m non-porous ODS as the stationary phase. Factors that affect the analysis time of samples, such as voltage, electrolyte concentration, pH and organic modifier concentration in the mobile phase, were studied systematically. Fast analysis of aromatic compounds within 13 seconds was realized with column efficiency of 573,000 plates/m and a R.S.D.% of the retention times of all components in 8 consecutive injections below 1.0%. which demonstrated the high efficiency and high reproducibility of such a technique. In addition, DNPH derived aldehydes and ketones in both standards and environmental samples were separated with high speed ...
An experimental study of parameters influencing peak shapes in ion-exchange open tubular (OT) capillary electrochromatography (CEC) was conducted using adsorbed quaternary aminated latex particles as the stationary phase. The combination of separation mechanisms from both capillary electrophoresis and ion-exchange chromatography results in peak broadening in OT-CEC arising from both these techniques. The sources of peak broadening that were considered included the relative electrophoretic mobilities of the eluent co-ion and analyte, and resistance to mass transfer in both the mobile and stationary phases. The parameters investigated were the mobility of the eluent co-ion, column diameter, separation temperature and secondary interactions between the analyte and the stationary phase. The electromigration dispersion was found to influence peak shapes to a minor extent, indicating that chromatographic retention was the dominant source of dispersion. Improving the resistance to mass transfer in the ...
article{350485, author = {Lynen, Frederic and BUICA, A and De Villiers, Andr{\e} and CROUCH, A and Sandra, Patrick}, issn = {1615-9306}, journal = {JOURNAL OF SEPARATION SCIENCE}, language = {eng}, number = {13}, pages = {1539--1549}, publisher = {WILEY-V C H VERLAG GMBH}, title = {An efficient slurry packing procedure for the preparation of columns applicable in capillary electrochromatography and capillary electrochromatography-electrospray-mass spectrometry}, volume = {28}, year = {2005 ...
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Capillary columns packed electrokinetically with 1.5-μm nonporous octadecylsilica particles are used to achieve rapid separations with high efficiencies. A mixture containing five polycyclic aromatic hydrocarbons (PAHs) as test compounds is separated in less than 5 s with 28 kV applied to a column with a packed length of 6.5 cm (10 cm total length). A sample containing 16 PAHs (classified as priority pollutants by the U.S. Environmental Protection Agency) is isocratically separated in under 10 min by using longer columns (15-30 cm). Separation efficiencies greater than 700 000 theoretical plates/m are obtained when detection (via UV-excited laser-induced fluorescence) is performed on the packed portion of the capillary. The outlet frit is observed to play an important role in determining column efficiency. The optimum flow rate for best separation efficiency occurs at ∼2 mm/s. The run-to-run reproducibility of the peak retention times on a single column is better than 1% (relative standard deviation)
Citation: N/A Interpretive Summary: Vitamin E and related compounds are important minor constituents of oilseeds. They provide many health benefits and are useful in oil preservation. State-of-the-art techniques are needed for studying the impact of the minor constituents on the quality and stability of vegetable oils. Separations of the vitamin-E active compounds in edible oils were evaluated by capillary electrochromatography. The new high-speed techniqu requires minimum solvent consumption. The technique can be used by seed growers and the food/oil industries for information on factors affecting oil quality/stability. Food scientists can utilize the optimized distribution data for improving food flavor and quality. Technical Abstract: Separations of lipid antioxidants, tocopherols (T), and tocotrienols (T3) on octylsilica (OS), octadecylsilica (ODS), phenylsilica, or silica were studied by capillary electrochromatography (CEC)-UV detection. The homologues and isomers of the vitamin E-active ...
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β-Cyclodextrin (β-CD) was anchored onto silica particles at its C(2) position, derivatized primarily at the C(6) position by treatment with bromoacetyl bromide, and finally reacted with two types of cyclams to form cyclam-capped β-CD-bonded silica particles. When used as chiral stationary phases in capillary electrochromatography, these novel bonded silica particles exhibited excellent enantioselectivities for chiral separations. © 2002 Elsevier Science Ltd. All rights reserved ...
This article looks at the use of electromigration techniques to determine microorganisms, such as viruses, bacteria and other biologically important macromolecules (erythrocytes), in medical analyses. It was found that electromigration techniques could be used for the identification of several viruses, including the identification of a specific marker for the Hepatitis C virus infection and another for a urinary tract infection. The determination of cell viability and the quality control of probiotics and consumer products that contain active bacteria is also possible using electromigration. Special attention is paid to the modification of capillary wall surfaces using different monomers and the application of monolithic columns to determine active bacteria in pharmaceutical products using capillary electrochromatography (CEC) conditions. This approach represents a new frontier for separation science and the possibility to apply it in medical diagnosis.
Nanoparticles were used as a pseudostationary phase in capillary electrochromatography (CEC) electrospray ionisation-mass spectrometry (ESI-MS) for separation of both neutral analytes by a reversed phase mechanism, as well as for cationic analytes by a cation exchange mechanism. Nanoparticles suspended in electrolyte, were injected as a plug prior to the sample using a partial filling technique (PF), or used as electrolyte in a continuous full filling (CFF) technique. An orthogonal ESI probe was used to hinder the nanoparticles from entering the mass spectrometer and to allow detection of analytes co-eluting with concentrated nanoparticle slurries. Two types of nanoparticles were synthesised and used, both of them having a hydrophobic core and a hydrophilic surface. The hydrophobic core gave the nanoparticles reversed phase properties and the hydrophilic surface promoted the formation of stable slurries of nanoparticles in electrolytes with a low concentration of organic modifier. The surface of ...
The introduction of therapeutic peptides and proteins can be an expensive and time-intensive process. between January 2012 and Dec 2013 publication within the within the two-year period. The parting principles and technical advancements of CE capillary gel electrophoresis capillary isoelectric concentrating capillary electrochromatography and CE-mass spectrometry are talked about alongside exciting brand-new applications of LY2603618 … Continue reading The introduction of therapeutic peptides and proteins can be an expensive. ...
The Journal of Liquid Chromatography and Related Technologies is an internationally acclaimed forum for fast publication of critical, peer reviewed manuscripts dealing with analytical, preparative and process scale liquid chromatography and all of its related technologies, including TLC, capillary electrophoresis, capillary electrochromatography,...
Microcalcifications can be the early and only presenting sign of breast cancer. One shared characteristic of breast cancer is the appearance of mammographic mammary microcalcifications that can routinely be used to detect breast cancer in its initial stages, which is of key importance due to the possibility that early detection allows the application of more conservative therapies for a better patient outcome. The mechanism by which mammary microcalcifications are formed is still largely unknown but breast cancers presenting microcalcifications are more often associated with a poorer prognosis. We combined Capillary Electrochromatography, histology, and gene expression (qRT-PCR) to analyze patient-matched normal breast tissue vs. breast tumor. Potential carcinogenicity of oxalate was tested by its inoculation into mice. All data were subjected to statistical analysis. To study the biological significance of oxalates within the breast tumor microenvironment, we measured oxalate concentration in both
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Fritless particle-loaded monoliths for chiral capillary electrochromatographic (CEC) separation were prepared. Silica particles containing a chiral selector are suspended in a monomer solution, which is drawn into the capillary followed by in situ polymerization. Thereby the silica-based particles containing the chiral selector are embedded in a nonchiral continuous bed. This kind of chiral stationary phase is inexpensive, easy, and reproducible to prepare and circumvents the preparation of frits. As a model, teicoplanin aglycone as chiral selector bonded to 3 μm silica particles was used. The applicability of this approach is demonstrated by means of the chiral separation of aliphatic and aromatic amino acids and dipeptides. As a further application, the chiral selector ristocetin A bonded to 3 μm silica particles was used for the enantiomeric separation of chiral α-hydroxy acids. Since α-hydroxy acids migrate toward the anode, a cationic charge-providing agent was copolymerized with the ...
The spatially controlled synthesis of poly(glycidyl methacrylate-co-ethylene dimethacrylate) monolithic stationary phases in polyimide coated fused silica capillaries by visible light induced radical polymerisation using a three-component initiator and a 660 nm light emitting diode (LED) as a light source is
This contribution relates to the assessment of gradient-elution parameters in capillary liquid chromatography affecting the peak widths in the reversed-phase separation of peptides and intact proteins. Gradient separations were performed using both a poly(sytrene-co-divinylbenzene) monolithic column and a microparticulate fused-core column (silica C18, 2.7 mu m). The applicability of the conventional linear (LSS) and non-linear solvent-strength model (Neue-Kuss) were investigated to describe the retention behaviour of the compounds as a function of the mobile-phase composition. This was performed by using a wide range of gradient conditions, including different gradient slopes (beta, ranging from 0.05 to 0.65 min(-1)) and mobile-phase compositions (Delta phi, i.e. gradient span). Although the LSS-model provided accurate retention time predictions (,1.3% deviation) of scouting runs with more conventional gradient slopes, the prediction of high-speed separations with a high degree of accuracy ...
A microchip laboratory system and method proved fluid manipulations for a variety of applications, including sample injection for microchip chemical separations. The microchip is fabricated using standard photolithographic procedures and chemical wet etching, with the substrate and cover plate joined using direct bonding. Capillary electrophoresis and electrochromatography are performed in channels formed in the substrate. Analytes are loaded into a four-way intersection of channels by electrokinetically pumping the analyte through the intersection, followed by switching of the potentials to force an analyte plug into the separation channel.
The Journal of Chromatography A publishes papers on all aspects of separation science including chromatography, electrochromatography, electrophoresis, hyphenated and other multi-dimensional techniques, sample preparation as well as detection methods such as mass spectrometry. .
An SDRAM memory chip device comprises a non-volatile memory controller for operating a non-volatile memory, e.g., a NAND-flash, and a FIFO memory buffer. The FIFO memory buffer serves to operate background store and load operations between a FIFO buffer array and the non-volatile memory, while a host system such as a CPU exchanges data with the SDRAM work memory. The SDRAM memory chip device, therefore, has at least two additional pins as compared with conventional SDRAM standard for generating a set of additional commands. These commands are employed by the FIFO memory buffer to manage the data transfer between the FIFO buffer and each of the non-volatile memory and the volatile SDRAM memory. Two further pins reflecting the flash memory status provide appropriate issuance of load or store signals by the host system.
An SDRAM memory chip device comprises a non-volatile memory controller for operating a non-volatile memory, e.g., a NAND-flash, and a FIFO memory buffer. The FIFO memory buffer serves to operate background store and load operations between a FIFO buffer array and the non-volatile memory, while a host system such as a CPU exchanges data with the SDRAM work memory. The SDRAM memory chip device, therefore, has at least two additional pins as compared with conventional SDRAM standard for generating a set of additional commands. These commands are employed by the FIFO memory buffer to manage the data transfer between the FIFO buffer and each of the non-volatile memory and the volatile SDRAM memory. Two further pins reflecting the flash memory status provide appropriate issuance of load or store signals by the host system.
臺大位居世界頂尖大學之列,為永久珍藏及向國際展現本校豐碩的研究成果及學術能量,圖書館整合機構典藏(NTUR)與學術庫(AH)不同功能平台,成為臺大學術典藏NTU scholars。期能整合研究能量、促進交流合作、保存學術產出、推廣研究成果。. To permanently archive and promote researcher profiles and scholarly works, Library integrates the services of NTU Repository with Academic Hub to form NTU Scholars.. ...
A method of preparing a polymer under predetermined temperature conditions comprises conducting the polymerization within a closed reaction chamber configured such that most or all of an inner surface has heat exchange capability. The chambers dimensions are such that the polymerization mixture contacts the effective heat exchange surface sufficiently to ensure that the temperature throughout the polymerization mixture does not vary more than a few degrees from a desired temperature. In one embodiment the chamber is formed of two adjacent, parallel heat exchange plates, wherein at least one plate has a peripheral lip which, in contact with the opposing plate, forms the closed chamber. Multiple plates can be arrayed to form multiple chambers, and each chambers polymerization temperature, as well as resident polymerization mixture, can be individually predetermined. This method and apparatus are particularly useful for preparing polymers used in drag reducing agents for hydrocarbon transportation
The major advantages of monolithic phases are their ability to withstand high mobile phase flow rates and the rapid separations at low back pressure that can be achieved with their use.
Measuring environmental concentrations of organic vapors with microfabricated chemical sensors or sensor arrays often requires a means to enrich collected samples prior to detection. With such an application in mind, a preliminary evaluation is described of two porous-layer open tubular (PLOT) capillary traps as vapor preconcentrators for a series of vapors. Short (1-cm) sections of commercial PLO
Chromatographic column technology in HPLC is an ever-growing field. One area in column technology that has captivated attention in recent years is the use of monolithic columns. Monolithic stationary phases for use in liquid chromatography possess unique characteristics, the most significant of which is a relatively high flow through porosity leading to low column pressure drops, with the potential for use with elevated flow rates leading to faster separations. Silica-based monolithic columns are the most popular phases currently for small molecule separations, although organic polymer-based monoliths have also been studies extensively. Within this thesis the preparation of carbon monoliths of varying flow through porosity for potential chromatographic and electrochemical applications is described. Carbon based monoliths can provide excellent chemical and thermal stability, surpassing those of silica. Unlike alternative materials, carbon monoliths have the advantage of being resistant to ...
D3437 Practice for Sampling and Handling Liquid Cyclic Products. D4307 Practice for Preparation of Liquid Blends for Use as Analytical Standards. D4790 Terminology of Aromatic Hydrocarbons and Related Chemicals. D6809 Guide for Quality Control and Quality Assurance Procedures for Aromatic Hydrocarbons and Related Materials. E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications. E355 Practice for Gas Chromatography Terms and Relationships. E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method. E1510 Practice for Installing Fused Silica Open Tubular Capillary Columns in Gas Chromatographs. ...
How is open-tubular liquid chromatography abbreviated? o-LC stands for open-tubular liquid chromatography. o-LC is defined as open-tubular liquid chromatography rarely.
Rapid chiral separation and impurity determination of ropivacaine and bupivacaine by Densitometry-HPTLC, using mucopolysaccharide as chiral mobile phase additive
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TY - JOUR. T1 - High-performance liquid chromatography of synthetic polymers on short monolithic columns.. AU - Maksimova, E.. AU - Vlakh, E.. AU - Sinitsyna, E.. AU - Tennikova., T.. PY - 2013. Y1 - 2013. M3 - статья. VL - 36. SP - 3741. EP - 3749. JO - Journal of Separation Science. JF - Journal of Separation Science. SN - 1615-9306. ER - ...
CIM® DEAE-8 mL tube is a cylindrical-shaped monolithic column with a column volume of 8 mL. It is encased in a specially designed housing and is
I. Mihelic, T. Koloini, A. Podgornik, A. Štrancar J. High Resol, Chromatogr. 2000, 23, (1) 39-43 The characterization of CIM® DEAE monolithic columns
abcr is ideally positioned in the area of chiral compounds. Learn more about the properties, synthesis and application fields of our chiral portfolio.
Labscoop is a global science eCommerce engine. Comparison shop millions of products from hundreds of vendors to ensure competitive pricing and reliability. Chiral Compounds Biochemicals & Reagents
The resistance to the mass transfer term for the stationary phase must be considered in isolation. The experimentally observed plate height (variance per unit length) resulting from a particular dispersion process [e.g., (hs), the resistance to mass transfer in the stationary phase] will be the sum of the local plate height contributions (h); i.e.,. ...
Scientists in New York and North Carolina say they have assembled the first functioning prototype of an artificial Golgi organelle, a key structure inside cells which helps process and package hormones, enzymes, and other substances that allow the body to function normally.
A method for separating plasma from red blood cells and a device utilizing the method in which a low-pressure filter is interposed in a pathway between an inlet port and a reaction area. The sole driving force for the movement of plasma from the filter to the reaction area is capillary force provided by a tubular capillary. The filter is selected from glass microfiber filters of specified characteristics, which can operate in the absence of agglutinins, and filters capable of separating agglutinated red cells from a plasma, which require the use of an agglutinin.
The present invention provides an endoprosthesis assembly having a reduced cross sectional profile for percutaneous deployment and implantation within a body passageway such as a blood vessel. The assembly comprises a radially expandable cylindrical frame having first and second ends, and a first unexpanded outer diameter and a second expanded outer diameter. The assembly further comprises a radially expandable elastomeric sleeve surrounding a length of the frame and having first and second ends and a first unexpanded inner diameter and a second expanded inner diameter. The inner diameter of the expanded sleeve is not greater than the outer diameter of the expanded frame. The second expanded inner diameter of the sleeve is in a range from about 60% to about 380% greater than the first unexpanded inner diameter of the sleeve. The assembly of the preferred embodiment is adapted to be deployed through an introducer smaller than 9 French and the sleeve is capable of expanding to an inner diameter of about
Novasep has recently added a state-of-the-art cGMP pilot scale continuous chromatography unit in its Chasse sur Rhône (France) facility. This ensures cost efficient separations of kilograms to ten ...
For 60 years, Regis Technologies, Inc. has partnered with pharmaceutical and biotechnology companies to help expedite drugs to market. ...
A global strategy for the analysis of glycoproteins by capillary electrophoresis and capillary liquid chromatography coupled to mass spectrometry. Application to quality control of biopharmaceuticals and disease diagnosis ...
PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
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Capillary electrophoresis (CE) comprises a family of related separation techniques in which an electric field is used to achieve the separation of components in a mixture. One of the key features of CE is the simplicity of the instrumentation required, and today, these techniques have become powerful analytical tools for high efficiency separation, and the identification of a variety of ionic and neutral compounds.. Moreover, the versatility of CE operational modes (capillary zone electrophoresis, micellar electrokinetic capillary chromatography, capillary electrochromatography, capillary isoelectric focusing, isotachophoresis, non-aqueous capillary electrophoresis, etc.) and detection systems (ultraviolet, fluorescence, amperometric, mass spectrometry…) make CE useful for applications in many fields such as environmental, food, pharmaceutical, and forensic analysis. The typcial drawback of CE techniques, based on their low sensitivity when dealing with conventional UV-detection, due to their ...
Studies of the capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MEKC) behaviour of 1,4-benzodiazepines have seen application in subject areas such as the development of pharmaceuticals, therapeutic drug monitoring and forensic toxicology. In the development of pharmaceuticals, pK(a) determinations by CZE can be used in preclinical studies whereas analytical data on the detection and determination of 1,4-benzodiazepines is of value primarily in raw material/formulation assay and in the analysis of body fluids in clinical studies. The capillary electrophoresis (CE) techniques, which generally have inferior limits of detection (LOD) to rival techniques such as gas chromatography (GC) and high-performance liquid chromatography (HPLC), are particularly applicable in forensic toxicology where reasonably high concentrations of these drugs can be encountered. It is anticipated that, with the interfacing of CZE: and capillary electrochromatography (CEC) with mass ...
Overview of Capillary Electrophoresis in Pharmaceutical Analysis -- Theoretical Consideration in Performance of Various Modes of CE -- Equipment Considerations for Capillary Electrophoresis -- Method Development for Pharmaceutical Analysis -- Role of CE in Drug Substance and Drug Product Development -- General Considerations to Improve Performance of CE Methods -- Overview of Current Regulatory Guidance -- Qualification of CE Instrumentation -- Robustness Testing of CE Methods -- Validation of Analytical Methods Using Capillary Electrophoresis-- The Need for CE Methods in Pharmacopeial Monographs -- CE in Impurity Profiling of Drugs -- Ion Analysis Using Capillary Electrophoresis -- Role of CE in Biopharmaceutical Development and Quality Control -- Capillary Electrophoresis and Bioanalysis -- CE as an Orthogonal Technique to Chromatography -- Capillary Electrochromatography of Pharmaceuticals -- Coupling CE and Chip-based Devices and Mass Spectrometry ...
A colloidal crystal is an ordered array of colloid particles, analogous to a standard crystal whose repeating subunits are atoms or molecules. A natural example of this phenomenon can be found in the gem opal, where spheres of silica assume a close-packed locally periodic structure under moderate compression. Bulk properties of a colloidal crystal depend on composition, particle size, packing arrangement, and degree of regularity. Applications include photonics, materials processing, and the study of self-assembly and phase transitions. IUPAC definition Assembly of colloid particles with a periodic structure that conforms to symmetries familiar from molecular or atomic crystals. Note: Colloidal crystals may be formed in a liquid medium or during drying of particle suspension. A colloidal crystal is a highly ordered array of particles which can be formed over a long range (to about a centimeter). Arrays such as this appear to be analogous to their atomic or molecular counterparts with proper ...
Chiral separations of five β-adrenergic antagonists (propranolol, esmolol, atenolol, metoprolol, and bisoprolol) were studied by capillary electrophoresis using six cyclodextrins (CDs) as the chiral selectors. Carboxymethylated-β-cyclodextrin (CM-β-CD) exhibited a higher enantioselectivity power compared to the other tested CDs. The influences of the concentration of CM-β-CD, buffer pH, buffer concentration, temperature, and applied voltage were investigated. The good chiral separation of five β-adrenergic antagonists was achieved using 50 mM Tris buffer at pH 4.0 containing 8 mM CM-β-CD with an applied voltage of 24 kV at 20 °C. In order to understand possible chiral recognition mechanisms of these racemates with CM-β-CD, host-guest binding procedures of CM-β-CD and these racemates were studied using the molecular docking software Autodock. The binding free energy was calculated using the Autodock semi-empirical binding free energy function. The results showed that the phenyl or naphthyl ring
TY - JOUR. T1 - Development of an affinity silica monolith containing α1-acid glycoprotein for chiral separations. AU - Mallik, Rangan. AU - Xuan, Hai. AU - Hage, David S.. PY - 2007/5/18. Y1 - 2007/5/18. N2 - An affinity monolith based on silica and containing immobilized α1-acid glycoprotein (AGP) was developed and evaluated in terms of its binding, efficiency and selectivity in chiral separations. The results were compared with data obtained for the same protein when used as a chiral stationary phase with HPLC-grade silica particles or monoliths based on a copolymer of glycidyl methacrylate (GMA) and ethylene dimethacrylate (EDMA). The surface coverage of AGP in the silica monolith was 18% higher than that obtained with silica particles and 61% higher than that measured for a GMA/EDMA monolith. The higher surface area of the silica monolith gave materials that contained 1.5- to 3.6-times more immobilized protein per unit volume when compared to silica particles or a GMA/EDMA monolith. The ...
TY - JOUR. T1 - Development of an affinity silica monolith containing α1-acid glycoprotein for chiral separations. AU - Mallik, Rangan. AU - Xuan, Hai. AU - Hage, David S.. PY - 2007/5/18. Y1 - 2007/5/18. N2 - An affinity monolith based on silica and containing immobilized α1-acid glycoprotein (AGP) was developed and evaluated in terms of its binding, efficiency and selectivity in chiral separations. The results were compared with data obtained for the same protein when used as a chiral stationary phase with HPLC-grade silica particles or monoliths based on a copolymer of glycidyl methacrylate (GMA) and ethylene dimethacrylate (EDMA). The surface coverage of AGP in the silica monolith was 18% higher than that obtained with silica particles and 61% higher than that measured for a GMA/EDMA monolith. The higher surface area of the silica monolith gave materials that contained 1.5- to 3.6-times more immobilized protein per unit volume when compared to silica particles or a GMA/EDMA monolith. The ...
Abstract: Many pharmaceuticals contain active ingredients that have more than one stereoisomer. An important concern is the recognition that these different stereoisomers do not necessarily have identical, or even desirable biological activity. Consequently, analytical methods for the analysis and separation of enantiomers are important in the proper development of a marketed pharmaceutical product. In this research, direct HPLC methods for the chromatographic separation of oxyphene optical isomers have been developed and optimized using three types of chiral stationary phases. The research carried out a systematic study of the conditions for the separation of oxyphene optical isomers using synthetic polymer chiral stationary phase of cellulose tris (3, 5-dimethylphenylcarbamate) Chiralcel OD, ß-cyclodextrin chiral stationary phase, and a1-acid glycoprotein chiral stationary phase. The methods using the ß-cyclodextrin and Chiralcel OD columns provide for the accurate determination of the ...
HPLC Application #23892: Chiral Separation of Nicardipine on Lux 3µm i-Cellulose-5. Column used: Lux® 3 µm i-Cellulose-5, LC Column 250 x 4.6 mm, Ea Part#: 00G-4755-E0
HPLC Application #24499: Chiral Separation of Chlorthalidone on Lux 5µm i-Amylose-1 in NP. Column used: Lux® 5 µm i-Amylose-1, LC Column 250 x 4.6 mm, Ea Part#: 00G-4762-E0
TY - JOUR. T1 - Nanoporous activated carbon beads and monolithic columns as effective hemoadsorbents for inflammatory cytokines. AU - Howell, Carol. AU - Sandeman, Susan. AU - Phillips, Gary. AU - Mikhalovsky, Sergey. AU - Tennison, S.R.. AU - Rawlinson, A.P.. AU - Kozynchenko, O.P.. PY - 2013/10/3. Y1 - 2013/10/3. N2 - The aim of the present study was to develop and investigate nanoporous activated carbon materials for their ability to adsorb inflammatory cytokines directly from blood, for a range of therapeutic applications, including: systemic inflammatory response syndrome (SIRS) related to sepsis, cardio-pulmonary by-pass surgery, or ischemic reperfusion injury. Building on the previously established relationship between the porous structure of beaded polymer-derived activated carbon and its capacity to adsorb inflammatory molecules, we have developed and characterized monolithic porous carbon columns produced from the same polymer precursor matrix as carbon microbeads. The monolithic ...
Rapid determination of theaflavins by HPLC with a new monolithic column | Jianyong Zhang, Hongchun Cui, Heyuan Jiang, Lei Fang, Weiwei Wang, Wei Su, Chunhua Xiong | Agricultural Journals
A simple capillary flow porometer (CFP) was assembled for pore structure characterization of monolithic capillary liquid chromatography columns based on ASTM standard F316-86. Determination of differential pressures and flow rates through dry and wet samples provided the necessary information to determine the through-pore throat diameter, bubble point pore diameter, mean flow pore diameter, and pore distribution. Unlike measurements in bulk using traditional techniques to provide indirect information about the pore properties of monolithic columns, monoliths can be characterized in their original chromatographic forms with this system. The performance of the new CFP was first evaluated by characterizing the pore size distributions of capillary columns packed with 3, 5, and 7 µm spherical silica particles. The mean through-pore diameters of the three packed columns were measured to be 0.5, 1.0 and 1.4 µm, which are all smaller than the pore diameters calculated from a close-packed arrangement (i.e., 0
Papaverine hydrochloride Spasm of smooth muscles: abdominal organs (cholecystitis, pilorospazm, spastic colitis, renal colic), peripheral vascular (occlusive disease), cerebrovascular, cardiac - angina (in the complex therapy), bronchospasm; as an auxiliary drug for sedation.
The effects of some factors important in ion-pair, high-performance liquid chromatography were studied in ion-pair, thin-layer chromatography. Tetramethyl and cetyltrimethylammonium salts were used...
The degree of acidity or alkalinity is an important property of our blood. The acidity level increases with the increase in the level of acidic compounds in our body, or when the level of basic (also known as alkaline) compounds present in our body falls. The alkalinity level in our body increases when the reverse takes place, i.e., when the level of acidic compounds falls or when the basic compounds in the body increase. The acidity or alkalinity of any solution is indicated on the pH scale. Even a minor shift from the normal range can destroy our organs. Generally, the normal acidic level (pH) of our blood is close to 7.4. When the pH level falls below 7.35, then we say that acidosis has occurred. On the other hand, when the pH goes above 7.45, then we say that alkalosis has occurred. We have a severe case of the former, when the pH value of blood goes below 7.0; while a severe case of the latter can occur when the pH value goes above 7.5. Let us now see what are the various causes and ...
Graphite Capillary Column Ferrule, Nut Size: 1/16in, Column Inner Diameter: 0.32mm, Ferrule Inner Diameter: 0.5mm (2-Hole), Pkg 10
In this work, a new oligomer matrix-assisted dispersion (OMAD) method for the preparation of homogeneous dispersion of multi-walled carbon nanotubes (MWNTs) incorporated monolithic column was developed. Oligomers matrix as a scaffold could allow MWNTs to entangle with it instead of self-aggregation, so the MWNTs remain in the polymer network followed by in situ self-solidification. The OMAD method not only greatly enlarged the BET surface area of MWNTs incorporated monolithic column from 13.8 m(2) g(-1) to 85.5 m(2) g(-1) without a significant effect on the surface chemistry of the MWNTs, but also improved the dispersion of MWNTs making its content up to 5 wt% (with respect to monomers). The synthesized materials combine the favorable attributes of both high permeability and large surface area, making them excellent candidates for on-line separation and enrichment of proteins. The oligomer matrix-assisted dispersion MWNTs incorporated monolithic columns (OMAD-MMC) exhibited higher enrichment ...
Modern Golden Leopard Scalloped Edge Dinnerware Set - 16 Pieces, Fine Bone China. Condition is Brand New. Awesome scalloped edge modern dinner set for four in the exclusive Golden Leopard design from Enchantée Fine Goods. The perfect luxury investment at a good price point. Includes four dinner plates, four entrée plates, four dessert bowls (also perfect for soups and cereals) and four mugs. Made from the highest grade fine bone china, this set is both durable and beautiful. Includes innovative gold ink gilding (with 10% real gold) that allows the set to also be safe to use in the oven, microwave, dishwasher and freezer. Dinner Plate - Height is 2.5cm and diameter is 28.7cm. Entrée Plate - Height is 2.4cm and diameter is 23.8cm. Dessert Bowl - Height is 8.4cm and greatest diameter is 14.3cm. Mug - Height is 11cm and greatest diameter is 11.5cm. These modern dinnerware sets are made from the highest grade fine bone china with over 40% bone ash where over 30% is the standard for high grade!!! ...
A team from the physics department of the Johannes Gutenberg University, Mainz, has investigated nucleation processes and interfacial properties of colloidal crystals. Nucleation is omnipresent in our daily life and describes events as diverse as the formation of rain in clouds, the crystallization of proteins or the growth of nano-particles. The studies undertaken using supercomputers Hazel Hen and Hornet of HLRS Stuttgart contribute towards a more fundamental understanding of these processes and the underlying theoretical foundation.
Researchers have developed and tested a prototype able to provide image data at 60 frames per second, and plan next to conduct animal studies that could lead to commercialization of the device.. Our device will allow doctors to see the whole volume that is in front of them within a blood vessel, said F. Levent Degertekin, a professor in the George W. Woodruff School of Mechanical Engineering at the Georgia Institute of Technology. This will give cardiologists the equivalent of a flashlight so they can see blockages ahead of them in occluded arteries. It has the potential for reducing the amount of surgery that must be done to clear these vessels.. Details of the research were published online in the February 2014 issue of the journal IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. Research leading to the device development was supported by the National Institute of Biomedical Imaging and Bioengineering (NIBIB), part of the National Institutes of Health.. If youre a ...
CHIRAL SEPARATION. In the area of chiral separations, Expert has developed many separations to detect the trace undesirable enantiomer. Expert is an instructor for the American Chemical Society short course Practical Capillary Electrophoresis and the author of the text with the same title. In addition, Expert has written a book on troubleshooting electrophoretic methods, has numerous publications in he field, and writes a monthly column that appears in American Laboratory ...
Principal Investigator:OKAMOTO Yoshio, Project Period (FY):1998 - 2000, Research Category:Grant-in-Aid for Scientific Research on Priority Areas (B)
Meropenem is a widely used antimicrobial for the treatment of infections associated with the use of invasive medical devices in intensive care unit patients. These treatments are not always effective, in fact, in-vitro studies have demonstrated the difficulty of antimicrobials to penetrate into the biofilm, however in-vivo studies of the effect of these compounds is a trend, mostly because of the complexity of pulmonary samples extracted from ETTs. Therefore, the objective of this study was to evaluate in-tube solid phase microextraction (in-tube SPME) coupled to capillary liquid chromatography (CapLC) with DAD to determine meropenem in ETTs in order to estimate the penetration capability into the biofilm ...
This project is funded by the National Science Foundation, grant # 0822241, 1449550, 1650648, 1743807, and 1813076. Any opinions, findings, and conclusions or recommendations expressed in these materials are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.. ...
Preparative Supercritical Fluid Chromatography (pSFC). As an environment-friendly approach to purification applications, pSFC is being used routinely for an increasing number of applications.. During the recent years SFC has gained acceptance in drug discovery for high-throughput purification of enantiomers. Hence, pSFC replaces preparative HPLC (pHPLC) as major technology for chiral separations in many pharmaceutical companies. Preparative SFC excels not only at separating and purifying chiral compounds but is also powerful for achiral separations and can be implemented in most steps of drug discovery. It may offer potential advantages over pHPLC for purity upgrading of active pharmaceutical ingredients or drug intermediates, impurity isolation and non-aqueous purification.. The use of pSFC as an alternative option to pHPLC receives also a growing interest for natural products, environmental (pesticides) and petroleum (biofuels) applications. ...
Preparative Supercritical Fluid Chromatography (pSFC). As an environment-friendly approach to purification applications, pSFC is being used routinely for an increasing number of applications.. During the recent years SFC has gained acceptance in drug discovery for high-throughput purification of enantiomers. Hence, pSFC replaces preparative HPLC (pHPLC) as major technology for chiral separations in many pharmaceutical companies. Preparative SFC excels not only at separating and purifying chiral compounds but is also powerful for achiral separations and can be implemented in most steps of drug discovery. It may offer potential advantages over pHPLC for purity upgrading of active pharmaceutical ingredients or drug intermediates, impurity isolation and non-aqueous purification.. The use of pSFC as an alternative option to pHPLC receives also a growing interest for natural products, environmental (pesticides) and petroleum (biofuels) applications. ...
D-glucopyranoside, also known as hexose or D-galactose, is a member of the class of compounds known as hexoses. Hexoses are monosaccharides in which the sugar unit is a is a six-carbon containing moeity. D-glucopyranoside is soluble (in water) and a very weakly acidic compound (based on its pKa). D-glucopyranoside can be found in a number of food items such as marzipan, olive, channel catfish, and rubus (blackberry, raspberry), which makes D-glucopyranoside a potential biomarker for the consumption of these food products. D-glucopyranoside exists in all living organisms, ranging from bacteria to humans. The name was originally given to plant products of this nature, in which the other part of the molecule was, in the greater number of cases, an aromatic aldehydic or phenolic compound (exceptions are sinigrin and jalapin or scammonin). It has now been extended to include synthetic ethers, such as those obtained by acting on alcoholic glucose solutions with hydrochloric acid, and also the ...
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( The below information some comes from the Internet and professional websites.) *** What do different LED mean? Like 5050, 3528, 2835, 5730 .... The abbreviation SMD refers to a Surface Mounted Device.That means this is an LED Chip (device) mounted directly to a light strip, without using wires.The Numbers mean th
High-performance liquid chromatography (HPLC) is a powerful tool for the enantioselective separation of chiral drugs. However, the selection of an appropriate chiral stationary phase (CSP) and suitable operating conditions is a bottleneck in method development and a time- and resource-consuming task. Multimodal screening of a small number of CSPs with broad enantiorecognition abilities has been recognized as the best strategy to achieve rapid and reliable separations of chiral compounds. This paper describes the generic screening strategy developed at Johnson & Johnson Pharmaceutical Research and Development to successfully develop enantioselective HPLC methods for chiral molecules of pharmaceutical interest. ...
The Chiral Chromatography Learning Center provides technical resources to help you choose a chiral HPLC or GC column, troubleshoot a chiral method, or enhance your understanding of chiral separations.
These kits provide the necessary columns to perform most chiral separations and run mechanistic studies, and are offered at very attractive prices.Supelco DEX Kit I is valuable for studying the effect of CD size on a separation. All three columns in the kit, α-DEX 120, β-DEX 120, and γ-DEX 120, have the same permethylated derivative, but on different size CDs. One application is to confirm enantiomer identification by monitoring elution order changes (enantioreversal) from one column to another. Supelco DEX Kit II contains four columns, each 30 m x 0.25 mm I.D., 0.25 μm, one each of β-DEX 120, β-DEX 225, γ-DEX 225, and β-DEX 325. Combining this kit with Supelco DEX Kit I spans the full range of Supelco DEX column enantioselectivity.
Previously determined retention data for a series of benzodiazepine (BDZ) derivatives, comprising nine achiral compounds, four single enantiomers, and 18 individual isomers of nine racemates, on a chiral stationary phase based on immobilized human serum albumin (HSA) were analyzed to define quantitative relationships between structure and enantiospecific retention. Structural parametrization of the agents was done by means of hydrophobic fragmental constants and electronic and steric parameters obtained by computational chemistry methods. A structural descriptor was identified, a submolecular measure of polarity about the stereogenic center, that accounted for the stronger electrostatic interactions of the second-eluting enantiomer with the HSA chiral stationary phase. Quantitative structure-enantiospecific retention relationships were derived for both enantiomeric series and for achiral compounds, and structural requirements for binding to HSA were determined. Two types of binding sites were ...
Monoliths, the latest track from Deerhunter guitarist Lockett Pundts solo project Lotus Plaza, is a lush, summery anthem. With layers of radiant guitars and a high-flying chorus, it conjures the wide-open spaces of a road trip through the plains states, or rope-swinging into an icy lake on a hot afternoon. Lotus Plazas second full-length, Spooky Action At A Distance, is out tomorrow on Kranky.. Stream: Lotus Plaza, Monoliths ...
Electrons in chiral crystals, solid-state materials with definite handedness, can behave in unexpected ways. An interdisciplinary team from research institutions in Germany and China has realized now a theoretically predicted peculiar electronic state in a chiral compound, PtGa, from the class of topological materials. The study which was published in the journal Nature Communications allows a fundamental understanding of the electronic properties of this novel semimetal.
UCP209-28 Black Oxide Plated Insert + Pillow Block Bearing Set Screw Type High-Center Height 1 3/4 inch Inner Diameter UCP209-28 Black Oxide Plated Insert Pillow Block Bearing, UCP209-28 is Set Screw Type High-Center Height, Inner Diameter is 1 3/4. Black oxide has certain properties and characteristics that makes
Pair this coupler with a sewer pipe adapter (sold separately) to connect a rigid drain pipe to your RVs waste valve. One end secures to a 3 diameter
Our mission is and has been to provide our customers with quality supplies and outstanding service, doing whatever it takes to solve a problem when it occurs.. ...
Flame Sampling Probe Assembly for PerkinElmer AS-90/90A/90 Plus/91/93 Plus/S10 Autosampler from PerkinElmer. A Sampling Probe Assembly Component.
The invention relates to particles with opalescent effect-especially 3-D structural color pigments-based on solid colloidal crystals of monodispersed spheres and the manufacturing processes suitable f
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Morton Grove, IL (PRWEB) June 01, 2015 -- Regis Technologies, Inc. is a recognized leader in developing and manufacturing of chiral stationary phases (CSPs)