Resolution stationary phase. Medical search. Frequent questions

The traditional bonding techniques used to manufacture silica-particle-based HPLC stationary phases provide many benefits, but can emerging technologies tackle unmet needs? (chromatographyonline.com)
This article will review historical bonding techniques still in use for manufacturing HPLC stationary phases today, and also examine some emerging technologies that may be able to tackle unmet needs in novel platforms and phase construction. (chromatographyonline.com)
In 1973, Locke correctly predicted that organosilanes would transform HPLC columns via chemically-bonded phases, mentioning that polymerization of silanes would be the synthetic route taken in general with chemical reactions being carried out to produce a primary organosilane layer (5). (chromatographyonline.com)
for example, if the sample includes polar analytes then reverse phase HPLC would offer both adequate retention and resolution, whereas normal phase HPLC would be much less feasible. (pharmtech.com)
For low/medium polarity analytes, normal phase HPLC is a potential candidate, particularly if the separation of isomers is required. (pharmtech.com)
This is only a requirement for complex samples with a large number of components (.20-30) because the maximum number of peaks that can be resolved with a given resolution is much higher than in isocratic HPLC. (pharmtech.com)
Reverse phase gradient HPLC is commonly used in peptide and small protein analysis using an acetonitrile-water mobile phase containing 1% trifluoroethanoic acid. (pharmtech.com)
The application of ionic liquids (ILs) as mobile modifiers for chromatographic separation of arsenite [As(III)], arsenate [As(V)], dimethylarsonic acid (DMA) and monomethylarsonic acid (MMA) species by reversed-phase high performance liquid chromatography coupled to hydride generation atomic fluorescence spectrometry detection (RP-HPLC-HG-AFS) was studied in this work. (conicet.gov.ar)
The separation mechanisms involved when ILs are used in RP-HPLC could be attributed to different processes, i.e. anion exchange between As species and ILs retained on the stationary phase, but also possible interaction of ion pairs formed between ILs and As species with the C18 stationary phase. (conicet.gov.ar)
The enantiodiscriminating capability of each one of these phases was evaluated by HPLC with four families of chiral aromatic compounds composed of alcohols, amines, phenylalanine and tryptophan amino acid derivatives and beta-lactams. (ua.pt)
TFA is widely used as a mobile phase additive in the HPLC separation of biological molecules, such as proteins and peptides, because it acts as an ion-pairing reagent and equilibrates quickly so that it can be used with gradient elution. (wazeesupperclub.com)
Reversed-phase chromatography is the most common HPLC separation technique and is used for separating compounds that have hydrophobic moieties and do not have a dominant polar character (although polarity of a compound does not exclude the use of RP-HPLC). (wazeesupperclub.com)
Founded on Core Enhanced Technology™ Thermo Scientific Accucore HPLC columns provide the UHPLC features of fast separations with superb resolution, but without the backpressures associated with this technique. (chromatographytoday.com)
Based on Core Enhanced Technology, a unique combination of state-of-the art particle technology from Thermo Fisher Scientific and vast experience in phase bonding and packing, Accucore™ HPLC columns provide ultimate chromatographic performance without any restriction on the type of HPLC instrument that can be used. (chromatographytoday.com)
Optimisation of HPLC systems with different combinations of mobile and stationary phases. (lu.se)

Almost 50 years later, the C18 phase is still the reigning champion in the reversed-phase liquid chromatography (RPLC) arena, and many chromatography companies are still bonding using the same or a very similar synthetic approach. (chromatographyonline.com)
According to the United States Pharmacopeia ( USP ), there are 858 C18 liquid chromatography phases registered under code L1 (octadecylsilane chemically bonded to porous silica or ceramic microplates, 1.5 to 10 μm in diameter, or a monolithic rod) (3). (chromatographyonline.com)
In GC, the mobile phase is an inert gas, usually helium or nitrogen, and the stationary phase is either a solid adsorbent, termed gas-solid chromatography (GSC), or a liquid adsorbed onto an inert support, termed gas-liquid chromatography (GLC, or just GC). (sigmaaldrich.com)
This work presents a study of the sorption of a pre-synthesized polysiloxane, poly(methyltetradecylsiloxane) - PMTDS, onto zirconized and titanized-silica particles that results in efficient stationary phases for reversed phase liquid chromatography. (scielo.br)
The polymeric coating of inorganic oxide particles has been a strategy for preparation of reversed stationary phases for high-performance liquid chromatography with low cost, good selectivity and high hydrolytic stability. (scielo.br)

UHPLC separation of R - and S -enantiomers of Besifloxacin hydrochloride on a new Chiralpak IE-3 column consisting of an immobilized amylose tris(3,5-dichlorophenylcarbamate) chiral stationary phase on 3 µm silica was studied. (springer.com)
The selection and effects of mobile phase solvents, additives, organic modifiers, and column temperature on retention, separation, and resolution were investigated and optimized. (springer.com)
The separation was accomplished under normal-phase conditions using a mobile phase composed of dichloromethane:isopropyl alcohol:trifluoroacetic acid:diethylamine (90:10:0.3:0.05 v/v/v/v) under isocratic mode of elution at 15 °C. The interactions between the analytes, additives, and the stationary phase were discussed and the most probable separation mechanism was proposed. (springer.com)
Mosiashvili L, Chankvetadze L, Farkas T, Chankvetadze B (2013) On the effect of basic and acidic additives on the separation of the enantiomers of some basic drugs with polysaccharide-based chiral selectors and polar organic mobile phases. (springer.com)
Chromatography is the separation of mixtures into their components as a result of differential distribution of the solutes in order for identification, analyses, purify and/or quantity of the mixture for a mobile medium and for a stationary absorbing medium. (majortests.com)
What is the basic principle for separation in normal phase, reversed phase, ion-exchange and gel permeation chromatography? (majortests.com)
In addition, the new phases were used wlth a novel combined triple eluent concentration, pH and flow gradient technique for the simultaneous separation of 18 nucleotides, nucleosides and nucleobases and the method developed as applied to the separation of nucleic acids precursors in yeastolate samples. (dcu.ie)
His research was in the areas of organic chemistry and analytical chemistry, particularly in molecular recognition and enantiomer separation using chiral stationary phases (CSPs). (illinois.edu)
From the simplest to the most challenging method, our GC column technology allows to deliver high performance, faster analysis with optimal resolution and separation of the most complex matrices. (chromatographyonline.com)
Several factors influencing the chromatographic separation of the As species, such as pH of the mobile phase, buffer solution concentration, buffer type, IL concentration and length of alkyl groups in ILs were evaluated. (conicet.gov.ar)
The complete separation of As species was achieved using a C18 column in isocratic mode with a mobile phase composed of 0.5% (v/v) [C8mim]Cl and 5% (v/v) methanol at pH 8.5. (conicet.gov.ar)
The ILs showed remarkable performance for the separation of As species, which was obtained within 18 min with a resolution higher than 0.83. (conicet.gov.ar)
Peaks are distributed across a 2D separation space based on different physicochemical properties, enhancing resolution and significantly reducing co-elution. (chromatographytoday.com)
The separation of fullerenes and their derivatives on four commercially available reversed-phase columns was investigated using liquid chroma¬tography/mass spectrometry with atmospheric pressure chemical ionization. (canada.ca)
Six different stationary phases, bonded using advanced technology and packed with highly controlled automated processes, result in highly reproducible, rugged columns that offer a wide range of selectivity to meet all your separation needs. (chromatographytoday.com)
The separation results showed that the µGCC with the FG-HKUST-1 composite stationary phase achieved a baseline separation of C1-C4 in 8 min. (bvsalud.org)
A low-viscosity mobile phase consisting of compressed trial organic matter in geosciences because the composition carbon dioxide is used in SFC to achieve fast and efficient of its phenols is an important indicator of the type of original separation. (lu.se)

The strength of compound-stationary phase interaction determines an analyte's retention time. (sigmaaldrich.com)
Zirconized silica-based phases were more chemically resistant, despite their strong retention of basic solutes. (scielo.br)
The ion-exchange properties of these new phases were investigated and the retention mechanism of Ions on these stationary phases elucidated. (dcu.ie)
These effects were exploited to demonstrate a previously unreported cation charge gradlent approach to anlon separations, resulting in considerable reductions in retention times whilst maintaining resolution. (dcu.ie)
An nvestigation into the retention of transltlon metal cations was also made and it was hown that cations could be simultaneously separated with inorganic anions, as anlonlc complexes with the eluent anion, on the new zwitterionlc phase. (dcu.ie)
The technique is often used in reversed-phase chromatography as a convenient method to control the retention of solutes. (wazeesupperclub.com)
In order to get the optimum retention of charged analytes, it is important to match the analyte log P or log D values to the degree of polarity of the stationary phase. (thermofisher.com)
For acidic analytes, a stationary phase with anion exchange properties will give increased retention. (thermofisher.com)
To increase analyte retention, select a mobile phase buffer pH at which the analyte is charged. (thermofisher.com)
A shift in peak retention or resolution, associated with a sudden increase in operating pressure beyond expected levels indicate column contamination. (thermofisher.com)
A mobile phase buffer pH that is close to the pKa of an analyte can cause retention time drift. (thermofisher.com)
This in turn could lead to column overload, reduced retention, and loss in resolution. (thermofisher.com)
The neutral silica support used in YMCbasic exhibits minimal secondary retention interactions, so selectivity is true reversed-phase. (ymcamerica.com)
The difference in the retention time between methane and ethane was 1.11 min, with a resolution of 9.2 for methane and ethane . (bvsalud.org)

The silica gel is the stationary phase, TLC uses a thin uniform layer of silica gel or alumina coated onto a piece of glass, metal or rigid plastic. (majortests.com)
The terpenoid chiral selectors dehydroabietic acid, 12,14-dinitrodehydroabietic acid and friedelin have been covalently linked to silica gel yielding three chiral stationary phases CSP 1, CSP 2 and CSP 3, respectively. (ua.pt)

Bill's final papers on chiral stationary phases came out not too long ago, in 2011 and 2016. (illinois.edu)
Bioanalytical chemistry and resolution of chiral drugs owe Bill a great debt. (illinois.edu)
The vernacular for a chiral stationary phase chromatography column remains a "Pirkle column," and colleagues and alumni fondly remember the "Pirkle-ator" solvent stills in RAL, and how he was always available for late-night mentorship with his big mug of tea in hand. (illinois.edu)
In order to understand the structural factors that govern the chiral molecular recognition ability of these phases, molecular dynamics simulations were carried out in the gas phase with binary diastereomeric complexes formed by the selectors of CSP 1 and CSP 2 and several amino acid derivatives. (ua.pt)
Lux Cellulose-3 and Cellulose-4, unique and complementary chiral stationary phases, are now available in a 10 µm particle size for preparative and batch chromatography applications. (labwrench.com)
The four 10 µm Lux Cellulose chiral phases benefit from Phenomenex's unique manufacturing process and silica coating technology. (labwrench.com)
Lux Cellulose-2 provides a second chiral selector, cellulose tris (3-chloro-4-methylphenylcarbamate) providing a unique chlorinated stationary phase with chiral recognition abilities that complement the Lux family of columns. (labwrench.com)
Lux Cellulose-3 utilizes Cellulose tris (4-methylbenzoate) as the chiral selector, a variant cellulose ester derivative that offers unique chiral recognition abilities to provide enantioseparation when other phases fail. (labwrench.com)
The successful resolution of chiral compounds requires more than one stationary phase and the more phases you have to choose from, the better your chances of resolving enantiomers," explains Marc Jacob, Ph.D., product manager for Phenomenex. (labwrench.com)
The racemic mixture synthesized was separated by a chiral stationary phase (CSP) column, Chiralpak AD-H, with n-hexane-EtOH-TFA-diethylamine (70:30:0.1:0.1) as the mobile phase. (unboundmedicine.com)

This polymer's surface contains reactive silanols (Si-OH) that offer a number of possibilities for the synthesis of chemically-bonded phases. (chromatographyonline.com)
In general, the chromatographic performance and chemical stability of metalized silica-based self-immobilized PMTDS phases were similar to conventional chemically bonded stationary phases. (scielo.br)

Normal and Reversed Phase Chromatography What is the relationship between polarity of the mobile phase vs. elution time and resolution in normal phase and reversed phase chromatography? (majortests.com)
Both phases offer the low to mid polarity phase, 6% cyanopropylphenyl methypolysilozane. (fishersci.com)
The role of mobile phase polarity, a mixture of n-hexane and propan-2-ol in different ratios, was also evaluated through molecular dynamics simulations in explicit solvent. (ua.pt)

High resolution and multidimensional mass spectrometry and 1D and 2D NMR spectroscopy indicated that L1334 is an unusual GPL that includes the glycopeptidolipid tetrapeptide core structure, two rhamnose residues, one 6-deoxytalose residue and one 3-methoxy C24 fatty acyl chain. (suny.edu)
In This Edition Modern & Practical Applications - Accelerating ADC Development with Mass Spectrometry - Implementing High-Resolution Ion Mobility into Peptide Mapping Workflows Chromatogr. (chromatographytoday.com)
Instrumentation and experimental techniques for high-resolution chromatography as well as linking of chromatography to mass spectrometry and its applications in e.g. food, drug and environmental analysis. (lu.se)

HRGC), has facilitated the analysis of compounds such as pyridine that can be measured by gas chromatography and has resulted in improvements in resolution and sensitivity. (cdc.gov)
Compounds in the sample partition between the column's stationary phase and the carrier gas. (sigmaaldrich.com)
Reversed-phase chromatography is a technique using alkyl chains covalently bonded to the stationary phase particles in order to create a hydrophobic stationary phase, which has a stronger affinity for hydrophobic or less polar compounds. (wazeesupperclub.com)
YMCbasic is a unique reversed-phase column designed for analysis of pharmaceuticals and basic compounds. (ymcamerica.com)

Two absorption type stationary phases: polydimethylsiloxane (PDMS) and polyacrylate (PA) have been found to be most effective for extraction of target analytes. (degruyter.com)
Low baseline noise enables improved limits of detection with enhanced resolution of low level analytes. (fishersci.com)
Every GC stationary phase comes in different sizes so you can find the perfect match for your target analytes. (chromatographyonline.com)
Reverse phase is the choice for the majority of samples, but if acidic or basic analytes are present then reverse phase ion suppression (for weak acids or bases) or reverse phase ion pairing (for strong acids or bases) should be used. (pharmtech.com)
Using aqueous sample solvent with high elution strength-which impairs the partitioning of the analytes into the stationary phase-is detrimental and results in peak broadening. (thermofisher.com)
This stationary phase utilizes a novel silica synthesis and state-of-the-art silane bonding to create a column which gives true reversed-phase character, high resolution, and excellent peak shape that is typically difficult to obtain when analyzing basic analytes. (ymcamerica.com)

For PEMM 1, a pair of series-coupled ucolumn chips with integrated heaters and temperature sensors and stationary phase of cross-linked polydimethylsiloxane (PDMS) is used for temperature-programmed chromatographic separations. (cdc.gov)

The sorbed materials, after 6 days at room temperature without any chemical or physical agent, denominated as self-immobilized stationary phase, present appropriate polymeric layer thicknesses that cover the metalized silica surfaces. (scielo.br)
The self-immobilization of polymer onto titanized silica particles produces more homogeneous polymeric coatings and stationary phases without silanophilic activity. (scielo.br)
A proposed mechanism for this unique ability combines the shape selectivity of polymeric phases, previously recognized for planar polycyclic aromatic hydro¬ carbons, and the different 'molecular footprints' of the isomers. (canada.ca)
With technological innovations like polymeric end-capping and phase stabilization, Imtakt columns are excellent choices for LC-MS work due to low bleed and high efficiency. (imtaktusa.com)

Over recent years development of ion chromatography (IC) has focused on new phase technologies to s~multaneously increase efficlency and vary selectivity. (dcu.ie)
Mobile phase composition, for example, is the most powerful way of optimizing selectivity whereas temperature has a minor effect and would only achieve small selectivity changes. (pharmtech.com)
After treatment, the clenbuterol imprinted polymers were packed into solid-phase extraction columns and the bleeding was estimated by quantifying the amount of template released in 10 ml of methanol-acetic acid (9 + 1 v/v). This was followed by an assessment of selectivity and recovery in comparison with non-treated material. (strath.ac.uk)
These two new phases join the existing purification media options of Cellulose-1 and Cellulose-2, providing a dependable, high-resolution screening set with a wide range of selectivity. (labwrench.com)

The high values of distribution coefficient (K fs ) in PDMS/water and PA/water systems (log K fs between 3.05 and 4.23) indicates the very high applicability of these stationary phases for determination of carbamazepine, clomipramine, chlorprothixene and clotrimazole in water samples. (degruyter.com)

CSP 3 also gives efficient resolution of the free amines. (ua.pt)

Although new synthetic approaches have been applied to reversed-phase ligands, the bulk of the commercially available phases are still manufactured via conventional methods (6). (chromatographyonline.com)

Pyridine is usually collected from the gas phase on a column of solid sorbent, such as Tenax Pyridine can be removed from aqueous or slurry samples by purge-and-trap techniques or as headspace gas. (cdc.gov)
Reversed-phase chromatography employs a polar (aqueous) mobile phase. (wazeesupperclub.com)
HILIC columns are less tolerant of short equilibration times than RPLC columns, mainly because the water in the aqueous layer within the stationary phase derives from the mobile phase and takes time to establish itself. (thermofisher.com)
In extreme cases of solubility issues, even the aqueous portion of the mobile phase can be replaced by polar non-aqueous solvents, in which case the technique is referred to as 'non-aqueous HILIC chromatography. (thermofisher.com)

It has made the choice of a stationary phase less important than was previously the case with packed columns. (cdc.gov)
TraceGOLD TG-624 GC Columns provide 90+% resolution of the first six gases in EPA Method 8260 and EPA Method 524.4. (fishersci.com)
Solid core particles with a tightly controlled diameter of 2.6µm allow high speed, superb resolution separations to be achieved without the backpressures associated with UHPLC columns. (chromatographytoday.com)
We have two wide pore (300Å) columns with either a C4-like bonded phase or C18. (imtaktusa.com)

Review the most significant factors for gc column selection: stationary phase, internal diameter, film thickness, and column length. (sigmaaldrich.com)

Direct immersion solid-phase microextraction has been optimized and applied to the simultaneous determination of the neutral and basic pharmaceuticals: caffeine, carbamazepine, clomipramine, chlorprothixene and clotrimazole at low concentrations in municipal wastewater. (degruyter.com)

For the sake of energy preservation, bacteria, upon transition to stationary phase, tone down their protein synthesis. (nih.gov)

Cyano-bonded phases are easier to work with than plain silica for normal phase separations. (pharmtech.com)
For the PEMM 2, a single ucolumn chip with three independently heated zones is used to afford more power-efficient, high-resolution, high-speed separations of VOC mixture components. (cdc.gov)

Increase the organic percentage in the mobile phase. (thermofisher.com)
Selecting an organic modifier for reversed-phase chr. (chromatographytoday.com)

Another possibility for preparation of the polymer-coated stationary phases with pre-synthesized polymers has been by the self-immobilization process. (scielo.br)

However, baseline resolution of nearly all the fullerenes (up to at least C96) was achieved with a 2-(1-pyrenyl) ethylsilica phase. (canada.ca)

The aim of the study was to reduce the bleeding to levels that would allow the use of the materials as affinity phases for extraction of clenbuterol from bovine urine at concentrations below 1 ng ml(-1). (strath.ac.uk)
The increase in hydrophobic character of the ion-pair results in a greater affinity for the reverse stationary phase and leads to sample resolution. (wazeesupperclub.com)

Increasing the buffer concentration can enhance hydrogen bonding between analyte and stationary phase, masking other secondary interactions and improving peak shape. (thermofisher.com)
groups bonded to the fullerene surface appear to disrupt adsorptive interactions between the fullerene molecular footprints and the stationary phases. (canada.ca)

Specifically, an optical security system embodying phase-encoding will be conceptualized as encryption means in conjunction with biometric measurements, with the general objective of producing an automatic, tamper-proof security system. (nsf.gov)
Emission measurements during different work tasks using both portable and stationary time-resolved instruments. (lu.se)

The vaporized sample is transported through a chromatographic column by the flow of inert gas that forms the mobile phase. (sigmaaldrich.com)
The sample is transported through the column by the flow of inert, gaseous mobile phase. (majortests.com)

The column itself contains a liquid stationary phase which is absorbed onto the surface of an inert solid. (majortests.com)
Reducing column bleed increases reproducibility of the stationary phase over time, resulting in greater run-to-run and batch-to-batch reproducibility. (fishersci.com)
1. Why you should care about column efficienc y - This post was dedicated to column efficiency and understanding how this parameter affects resolution. (barts-blog.net)
running approximately 20 column volumes of mobile phase is recommended. (thermofisher.com)
Micro gas chromatographic column with copper benzene-1,3,5-tricarboxylate modified by multilayer fluorinated graphene as a stationary phase. (bvsalud.org)
The FG-HKUST-1 composite was used as a stationary phase for a micro gas chromatography column (µGCC) fabricated using micro-electro-mechanical system ( MEMS ) technology . (bvsalud.org)

Thus, resolution of As species was observed to be strongly dependant on the alkyl chain length of imidazolium-type ILs. (conicet.gov.ar)
The stationary phase is a monomeric bonding of several different alkyl silanes with chain lengths of C8 and smaller. (ymcamerica.com)

The resolution of individual fullerene isomers, on the other hand, was best accomplished with a poly¬ meric octadecylsilica bonded phase. (canada.ca)

For mycobacteria such as Myco- understood, partly because no molecular typing method bacterium tuberculosis and M. ulcerans , low intraspecies with suffi ciently high resolution for microepidemiologic diversity limits the use of genetic fi ngerprinting techniques analyses is available. (cdc.gov)
Laboratory sessions (7.5 credits): Experimental techniques for high-resolution chromatography. (lu.se)
Using the high-resolution imaging of EUS, the morphological features of various cys- tadenomas have recently been defined. (binaryoptionsforex625.com)

This Small Business Innovation Research Phase I project will demonstrate a new class of optical devices that will form the heart of a low-cost, versatile, field-usable environmental monitoring system to be developed in Phase II. (nsf.gov)
Senator Murkowski's resolution of disapproval is an attempt to stop the Environmental Protection Agency (EPA) from regulating greenhouse gas emissions under the Clean Air Act. (atr.org)

The ionic samples form an ion-pair with ion-pair reagents in the mobile phase to become electrically neutral. (wazeesupperclub.com)
As samples become more and more complex, scientists are likely to search for higher resolution possibilities even at the cost of higher pressure generation. (barts-blog.net)

Over the past 60 years, due to the advancement of hemo- the Work Group and tasked it with planning, developing, dialysis (HD) technology and the introduction of medical reviewing, and disseminating appropriate HD treatment insurance, dialysis treatment has become widespread, en- guidelines in accordance with international standards. (bvsalud.org)

Anatomy5

Organisms30

Diseases1

Chemicals and Drugs101

Analytical, Diagnostic and Therapeutic Techniques and Equipment53

Phenomena and Processes69

Disciplines and Occupations2

Technology, Industry, Agriculture4

Information Science10

Health Care5

HPLC15

Liquid chromatography5

Separation17

Retention14

Silica gel2

Chiral10

Chemically-bonded2

Polarity3

Mass spectrometry3

Compounds4

Analytes6

Polydimethylsiloxane1

Polymeric4

Selectivity4

PDMS1

Amines1

Commercially available1

Aqueous4

Columns4

Diameter1

Simultaneous1

Synthesis1

Separations2

Organic2

Polymers1

Baseline1

Affinity2

Interactions2

Measurements2

Flow of inert2

Column6

Alkyl2

Isomers1

High resolution3

Environmental2

Samples2

Introduction1