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Liquid ChromatographyChemically-bondedHPLCChiralSilica-basedPolar stationaryChromatographic separationSolutePolarityHydrophobicHydrophilicRetentionPrincipleAminoOrganicMobile phasePolymerSolutesMixturesElutionFlowsSimultaneousInteractionsSelectivityFunctional groupsCompoundsCommonlyConventionalHydroxyl groupsNormal phaseCapabilityDerivativesColumnAnalytesPurificationSurfaceCombinationBrowseReverseHighTypeMaterials
Liquid Chromatography8
  • 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)
  • 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)
  • Thermodynamic studies of a zwitterionic stationary phase in hydrophilic interaction liquid chromatography. (illumina.com)
  • Hydrophilic interaction liquid chromatography (HILIC) provides an alternative approach to effectively separate small polar compounds on polar stationary phases. (springer.com)
  • Normal or reversed-phase liquid chromatography can be used for analysis. (springer.com)
  • For historical reasons, it has been reported that HILIC is a variant of normal phase liquid chromatography, but the separation mechanism used in HILIC is more complicated than that in NP-LC. (springer.com)
Chemically-bonded4
  • 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 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)
  • 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)
  • The relationship between the structure and chromatographic properties of silica is discussed and the preparation and properties of chemically-bonded stationary phases based on silica are reviewed. (warwick.ac.uk)
HPLC5
  • 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)
  • Mechanisms of chiral discrimination by these and other types of chiral HPLC phases are discussed in terms of the interactions between functionalitles in the stationary phase and solute enantiomers. (warwick.ac.uk)
  • 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)
  • The 2D-HPLC system incorporated strong cation exchange and reversed phase separation modes. (cdc.gov)
Chiral6
  • Whilst it is currently common practice to use very wide pore (up to 4000 Angstrom) silicas as supports for carbohydrate carbamate phases, it was concluded from the present work that there is little or no justification for using such supports and that good chromatographic performance and effective chiral discrimination can be achieved on much smaller pore (e. g. 500 Angstrom), higher surface area materials. (warwick.ac.uk)
  • The naphthyl carbamate phase showed no resolving ability for any of these racemates and this appeared to correlate with the presence of N-H bands in the it spectrum which were indicative of severe disruption of the organised, H-bonded 3-dimensional structure necessary for chiral discrimination. (warwick.ac.uk)
  • By modifying the matrix or bonding different groups, different separation types of stationary phases are formed, which usually include: normal phase, reverse phase, ion exchange, size exclusion, chiral, and other stationary phases. (flashcolumns.com)
  • The chromatographic performances of four coated and immobilized amylose phenylcarbamate-based chiral columns were evaluated and compared under normal phase (NP) elution conditions by using chiral 4,4'-bipyridine derivatives as analytes. (unive.it)
  • 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)
  • 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)
Silica-based1
  • Zirconized silica-based phases were more chemically resistant, despite their strong retention of basic solutes. (scielo.br)
Polar stationary3
  • This technique consists of a polar mobile phase and a non-polar(less polar) stationary phase. (chemistnotes.com)
  • If the analyte molecule is more non-polar (molar hydrophobic), it will spend more time on the non-polar stationary phase. (chemistnotes.com)
  • The major difference between the normal phase column and the reverse phase column is that the normal phase column consists of a polar stationary phase and a non-polar mobile phase while the reverse phase column consists of a non-polar stationary phase and a polar mobile phase. (chemistnotes.com)
Chromatographic separation1
  • This approach minimizes the use of volatile organic solvents typically used in TLC protocols, while varying the selectivity of chromatographic separation by using multiple phenylandoctyl-modified stationary phases printed on a silica gel TLC plate. (ateneo.edu)
Solute2
  • The other four carbamate phases all showed resolving ability, each with its own specific pattern of solute selectivity. (warwick.ac.uk)
  • The water in the mobile phase repels the non-polar regions of the solute molecules which facilitates their interaction with the non-polar functional groups of the stationary phase (Non-polar). (chemistnotes.com)
Polarity4
  • 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)
  • The chromatographic mode in which the polarity of the modified groups on the matrix is greater than the polarity of the mobile phase is called normal phase chromatography, which relies on the different polarity of the sample to distribute between the stationary phase and the mobile phase to achieve separation. (flashcolumns.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)
  • The retention increases as the polarity of the mobile phase decreases, and thus polar analytes are more strongly retained than nonpolar ones. (springer.com)
Hydrophobic2
  • After modification, it has a wide range of applications in the separation and purification of biomolecules such as proteins and carbohydrates in ion exchange chromatography, size exclusion chromatography, and reversed-phase hydrophobic chromatography. (flashcolumns.com)
  • Moreover, octyl(C8), hexyl(C6), propyl(C3), ethyl (C2), phenyl, and cyclohexyl functional groups are bonded to a silica surface which makes the silica stationary phase nonpolar and hydrophobic. (chemistnotes.com)
Hydrophilic1
  • The characteristics of the hydrophilic stationary phase may affect and in some cases limit the choices of mobile phase composition, ion strength or buffer pH value available, since mechanisms other than hydrophilic partitioning could potentially occur. (springer.com)
Retention7
  • The ion-exchange properties of these new phases were investigated and the retention mechanism of Ions on these stationary phases elucidated. (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)
  • It was shown that the retention of solutes by these phases correlated directly with the w/w phase loading, whilst both the separation factor and resolution for various enantiomers displayed a more complex relationship. (warwick.ac.uk)
  • This phenomenon is responsible for the retention in reverse-phase chromatography. (chemistnotes.com)
  • n-Hexane/2-propanol 90:10 and n-hexane/2-propanol/methanol 90:5:5 mixtures were employed as mobile phases (MPs), and the effect of adding methanol in the MP on retention and selectivity was considered. (unive.it)
  • A desirable mobile phase would contain high organic content for better sensitivity and also show good on-column retention for polar ionic compounds. (springer.com)
  • By utilizing a three-way ANOVA, the composition of the mobile phase has been shown to have a significant effect on deuterated acetonitrile and other investigated void volume markers, demonstrating the fact that both void volume markers and acetonitrile itself exhibit retention-like behaviour. (lu.se)
Principle2
  • What is the basic principle for separation in normal phase, reversed phase, ion-exchange and gel permeation chromatography? (majortests.com)
  • Using the principle of stationary phase, we can approximate the propagation over a terrain (the PO approximation of the vector problem with a 3-D surface) with a 2-D surface. (intechopen.com)
Amino1
  • All three phases resolve well the racemates of N-trifluoracetyl and N-3,5-dinitrobenzoyl phenylalanine amino acid ester derivatives. (ua.pt)
Organic5
  • The matrix is the basic material composed of the stationary phase, and the commonly used matrix materials are divided into three categories: inorganic, organic, and composite materials. (flashcolumns.com)
  • However, compared with inorganic substrates such as silica gel, the separation mechanical strength that the organic matrix stationary phase can withstand is lower, and the separation and purification effect is poor, which limits its scope of application in purification. (flashcolumns.com)
  • The composite matrix is compatible with and neutralizes the advantages and disadvantages of the inorganic matrix and the organic matrix, but the corresponding stationary phase of the composite matrix is generally expensive, so it is less used in preparation and purification. (flashcolumns.com)
  • Typically, in reverse phase comprises water and water-miscible organic solvents like methanol, acetonitrile, and tetrahydrofuran. (chemistnotes.com)
  • 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)
Mobile phase8
  • The sample is transported through the column by the flow of inert, gaseous mobile phase. (majortests.com)
  • Solvent (mobile phase) is then made to flow through the silica bed (under gravity or pressure). (janisb.best)
  • In reverse-phase chromatography, the mobile phase is more polar than the stationary phase. (chemistnotes.com)
  • The individual components are separated between a stationary phase (the tubular column in a column) and a mobile phase, which flows through the stationary packing (in this case a liquid). (burkert.com)
  • Polar samples always show good solubility in the aqueous mobile phase used in HILIC, which overcomes the drawbacks of the poor solubility often encountered in NP-LC. (springer.com)
  • The comparison of void volumes, obtained with conventional neutral void volume markers, revealed the former to be 24-36% lower than the void volume obtained using deuterated acetonitrile, as an isotopically labelled mobile phase component. (lu.se)
  • For a water:acetonitrile mobile phase, the minor disturbance method using deuterated acetonitrile to obtain an integral average void volume (2.08 and 2.05 mL for C18 at 30 and 40 °C, respectively and 2.16 and 2.13 mL for C8 at 30 and 40 °C, respectively) was found to be the most appropriate method for determining the elusive column void volume. (lu.se)
  • UHPSFC , ultra- pacted by other parameters, such as the addition of the mod- high performance supercritical fluid chromatography ifier and the change of the mobile phase density [20]. (lu.se)
Polymer4
  • The self-immobilization of polymer onto titanized silica particles produces more homogeneous polymeric coatings and stationary phases without silanophilic activity. (scielo.br)
  • The preparation of phases may occur by cross-linking of a polymer initiated by a chemical agent 5 5 Figge, H. (scielo.br)
  • Another possibility for preparation of the polymer-coated stationary phases with pre-synthesized polymers has been by the self-immobilization process. (scielo.br)
  • Hamilton offers 21 polymer-based stationary phases as well as two silica gels (C8 and C18) to satisfy most separation/purification needs. (hamiltoncompany.com)
Solutes1
  • 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)
Mixtures1
  • The tri(2-hexanamido)ethylamine core IL series proved to be very interesting in that it not only showed the highest separation efficiency for all test mixtures, but it also is the first IL stationary phase (containing NTf 2 − anions) that eliminates peak tailing for alcohols and other H-bonding analytes. (figshare.com)
Elution1
  • 24 compounds were separated 36% faster with an elution window increase of 33% on the ionic liquid phase compared to the 5% diphenyl/95% dimethylpolysiloxane phase. (ojp.gov)
Flows1
  • The different components of the analyte exhibit varying degrees of adhesion to the silica (see later), and as a result they travel at different speeds through the stationary phase as the solvent flows through it, indicated by the separation of the different bands. (janisb.best)
Simultaneous1
  • 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)
Interactions1
  • Due to the various velocities at which all liquids are pumped through the system, individual components can be separated based on the different flow properties and varying interactions between the stationary and the mobile phases of the substances. (burkert.com)
Selectivity2
  • Over recent years development of ion chromatography (IC) has focused on new phase technologies to s~multaneously increase efficlency and vary selectivity. (dcu.ie)
  • The selectivity of 11 isomeric analogue sets (out of 12) increased by 2 to 25% over the 5% diphenyl/95% dimethylpolysiloxane phase showing an ionic liquid column is more favorable for separating fentanyl analogues. (ojp.gov)
Functional groups1
  • To increase selectlvlty it IS necessary to develop new selective ]on-exchangers by varying the nature of functional groups and the matrix of the statlonary phase. (dcu.ie)
Compounds2
  • The purpose of this work was to review the options for the characterization of HILIC stationary phases and their applications for separations of polar compounds in complex matrices. (springer.com)
  • For example, it is suitable for analyzing compounds in complex systems that always elute near the void in reserved-phase chromatography. (springer.com)
Commonly1
Conventional1
  • 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)
Hydroxyl groups1
  • These phases were prepared by the exhaustive reaction of free hydroxyl groups in carbohydrates, such as cellulose and amylose, with aryl isocyanates, such as phenyl isocyanate and 3,5-dimethylphenyl isocyanate. (warwick.ac.uk)
Normal phase2
  • It is used in normal-phase purification systems. (flashcolumns.com)
  • However, it is difficult to modify the surface of alumina, so it is still used in normal phase purification systems at most and a small amount in ion exchange systems. (flashcolumns.com)
Capability1
  • In the experimental part, the thesis describes work carried out to study the effects of stationary phase support properties on the chromatographic behaviour and enantiomer resolution capability of carbohydrate carbamate phases. (warwick.ac.uk)
Derivatives2
  • A detailed account is given of the history of the development of carbohydrate-based stationary phases, including microcrystalline cellulose, other polysaccharides and monosaccharides and their ester and carbamate derivatives, with emphasis on their utility for the chromatographic resolution of enantiomers. (warwick.ac.uk)
  • The CSP 3 phase, containing a selector with a large friedelane backbone is particularly suitable for resolving free alcohols and their derivatives bearing fluorine substituents, while CSP 2 with a dehydroabietic architecture is the only phase that efficiently discriminates 1, 1'-binaphthol atropisomers. (ua.pt)
Column4
  • The column itself contains a liquid stationary phase which is absorbed onto the surface of an inert solid. (majortests.com)
  • Today HAWACH will talk about the connotation of the purification column-stationary phase. (flashcolumns.com)
  • To determine the stationary phase packed in the Flash purification column, three aspects of the stationary phase must be determined in sequence: matrix type, surface modification/bonding phase, and matrix parameters. (flashcolumns.com)
  • Hamilton gives you control to build any column to your specifications with any of our stationary phases in any combination of our column hardware formats. (hamiltoncompany.com)
Analytes1
  • Two absorption type stationary phases: polydimethylsiloxane (PDMS) and polyacrylate (PA) have been found to be most effective for extraction of target analytes. (degruyter.com)
Purification1
  • There are many kinds of stationary phases modified with a silica gel matrix, and the separation and purification effect is much better than other matrixes. (flashcolumns.com)
Surface2
  • The influence of changing pore diameter of the aminopropylated silica, with concomitant changes in pore volume and surface area, were evaluated for a series of materials at constant w/w phase loading. (warwick.ac.uk)
  • At the same time, the surface of silica gel is easily modified to form other bonded stationary phases. (flashcolumns.com)
Combination1
  • ii) the recovery and clean-up phase, which, depending on the severity of the accident, may require extensive individual prospective dose assessments, and iii) the long-term phase when measures are done to restore life conditions to pre-accident conditions in affected areas, during which a system for individual dosimetry in combination with stationary and mobile assessments will be required to ascertain the involved stakeholders. (lu.se)
Browse1
  • If you need to follow a specific USP monograph, browse our USP qualified stationary phases. (hamiltoncompany.com)
Reverse1
  • Among the various separation techniques available at an analytical scale, reverse phase chromatography is the most favored and widely used method. (chemistnotes.com)
High1
  • 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)
Type1
  • It appears that this specific type of multifunctional ILs may have the most promising future as a new generation of gas chromatographic stationary phases. (figshare.com)
Materials1
  • 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)