349 Results for: "Mobile phases and phase modifiers"

Supplier: Merck

Aluminium oxide, γ-phase

Supplier: Merck

Our NH₂, CN- and DIOL-modified silica sorbents are less polar then conventional silica phases, making them ideal for separating hydrophilic or charged substances. Our moderately polar cyano- and diol-modified silica plates can be used for both normal phase and reversed phase systems. An alternative to PEI cellulose, amino-modified NH₂ plates provide weak basic ion exchange characteristics with special selectivity for charged compounds.

Supplier: Merck

LiChrolut® solid phase extraction (SPE) cartridges and accessories are manufactured to the highest standards. All SPE cartridges listed below are polypropylene unless otherwise stated. They are compatible with all automated SPE instruments and robots. Three important criteria are carefully controlled.

Supplier: Merck

This non-polar column is specially designed for reproducible analyses of plant sterols, cholesterol, and other animal sterols.

Supplier: Merck

These non-polar methyl silicone bonded poly(dimethyl siloxane) columns are used to separate the sample components according to boiling point.

Supplier: Merck

Solid phase extraction disks provides faster flow rates and exhibits less clogging than PTFE discs for the extraction of organic contaminants from drinking water samples.

Supplier: Merck

This intermediate polarity column is mainly designed for analyses of volatile organic compounds (VOCs), offers great retention and resolution of highly volatile compounds.

Supplier: Merck

These bonded poly(5% diphenyl/95% dimethylsiloxane) low phenyl content columns improve thermal stability of the phase, while still providing essentially a boiling point elution order, and a slight increase in selectivity, especially for aromatic compounds.

Supplier: Merck

These columns are situated between the traditional non bonded cyanosilicone phases SP-2330 and SP-2340 in polarity. The high polarity of this phase allows the separation of geometric (cis/trans) fatty acid methyl ester isomers as a group.

Supplier: Merck

This column provides boiling point elution order with a slight increase in selectivity, especially for aromatic compounds.

Supplier: Merck

This column is specially designed for purge-and-trap analyses of volatile halogenated, non-halogenated, and aromatic contaminants from environmental samples.

Supplier: Merck

These bonded SUPELCOWAX® 10 columns are widely used for separation and purity analyses of many polar compounds, including alcohols, aromatics, and other solvents, flavors, fragrances and FAMEs.

Supplier: Merck

These are ionic liquid GC columns. They offer a great choice for analysis of neutral and polarisable (contain double and/or triple C-C bonds) analytes.

Supplier: Merck

CN- and DIOL-modified silica plates are moderately polar that are suitable for both normal and reversed phase systems. The amino modified NH₂ plate provides weak basic ion exchange characteristics with special selectivity for charged compounds offering an alternative to PEI cellulose.

Supplier: Merck

HPLC Standard, Reversed Phase Test Mix 2, TraceCERT®, Supelco®, in acetonitrile: water (varied conc.) solution, Certified reference material, Pk Info: ampule of 1 mL

Supplier: Merck

Chromolith® DIOL columns are useful as an intermediate polarity media between C18 and silica. Diol functionalised media is less polar and can have different selectivity. Chromolith® DIOL can be used with a wide range of solvents in both normal and reverse phases. In normal phase mode, the diol phase provides an alternative selectivity compared to silica whilst additionally demonstrating longer retention times that help to obtain separation. In reverse phase mode, compounds such as water-soluble vitamins, sugars or amino acids are easily baseline separated using simple mobile phases. Chromolith® DIOL columns have long lifetimes within pH range of 2,5 to 7,5, high matrix tolerance and speed of analysis.

Supplier: Merck

Fast method development of complex samples across the pH range from 1,5 to 10,5 with different mobile phases and temperature conditions.
Purospher® STAR RP-18 endcapped HPLC columns are designed for universal use. Basic, neutral and metal-chelating compounds can easily be separated with simple mobile phases – naturally without peak tailing. Thanks to its outstanding performance and stability, Purospher® STAR RP-18 endcapped offers maximum flexibility in method development. Robust methods can be developed over the entire pH range from 1,5 to 10,5. High pH-stability allows the separation of strongly basic compounds with alkaline eluents. The combination of high purity silica, best all-round retention characteristics, outstanding pH stability up to pH 10,5, and suitability for up to 100% aqueous mobile phases, make Purospher® STAR RP-18 endcapped an all-round top performance column, almost universal in its range of applications.

Supplier: Merck

Discovery® BIO Wide Pore reversed-phase columns satisfy the need for efficiency, selectivity, scalability, and reproducibility for RP HPLC analyses of proteins, peptides, and small biomolecules.

Supplier: Merck

Discovery® BIO Wide Pore reversed-phase columns satisfy the need for efficiency, selectivity, scalability, and reproducibility for RP HPLC analyses of proteins, peptides, and small biomolecules.

Supplier: Merck

Discovery® BIO Wide Pore reversed-phase columns satisfy the need for efficiency, selectivity, scalability, and reproducibility for RP HPLC analyses of proteins, peptides, and small biomolecules.

Supplier: Merck

Purospher® RP-18 is designed for the separation of problematic basic compounds with simple neutral eluents. In addition Purospher® RP-18 allows the separation of hydrophilic compounds with aqueous mobile phase. Purospher® RP-18 is based upon a high purity, metal-free silica. The multi-step chemical modification and deactivation of the surface, and the polar endcapping, enables a peak-tailing-free elution of basic and chelating compounds. Purospher® RP-18 is not suitable for the separation of acidic compounds. The good chemical stability of Purospher® RP-18 enables the use of mobile phase conditions at pH 8 for a long period of time.

Supplier: Merck

Polydimethylsiloxane + Polydiphenylsiloxane, ~500 mPa.s (25 °C) (1:1) DC-710 stationary phase for GC, Supelco®

Supplier: Merck

The Ascentis® Express PCS-C18 columns are designed for effective separation of basic, acidic, or neutral compounds using low ionic strength (formic acid) mobile phase conditions.

Supplier: Merck

HPLC Standard, Reversed Phase Test Mix, in methanol: water (3:2) (varied conc.), TraceCERT®, Supelco®, Certified reference material, Pk Info: ampule of 1 mL

Supplier: Merck

Silica based SUPELCOSIL™ LC-NH₂ columns separate monosaccharides, disaccharides, and some trisaccharides, with elution generally in order of increasing molecular weight. Retention decreases as the proportion of water:acetonitrile in the mobile phase is increased.

Supplier: Merck

These PTFE white hydrophilic membrane compatible with all commonly used HPLC solvents. The membrane undergoes a special treatment process to remove any residual extractables, to provide clearer analysis results. They are widely used for HPLC mobile phase filtration, clarifying acids, bases and dilute protein solutions and isolation of RNA.

Supplier: Merck

Brockmann aluminum oxides are suitable for column chromatography and adsorptive filtration. Aluminum oxides are generally used as solid support phases in solid phase extraction (SPE)-based clean-up procedures employed in chromatographic methods

Supplier: Merck

These screw cap valve (SCV) bags are suitable for calibration mixes - gas phase standards/gas mixtures.

Supplier: Merck

The LC-NH2-NP is an amino phase dedicated to normal phase chromatography suitable for separation of wate insoluble analytes like fat soluble vitamins.

Supplier: Merck

Promecarb may be used as a reference standard for the determination of promecarb in water by solid-phase extraction and liquid chromatography coupled with ionspray mass spectrometry.