740 Results for: "Mobile phases and phase modifiers"

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

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

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

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

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.

Supplier: Merck

The LC-ABZ phase has a unique deactivation technology which provides excellent reversed-phase performance for basic compounds, as well as those that are acidic, polar neutral, and non-polar.

Supplier: Merck

These SUPELCOSIL LC-DB phases are specially deactivated for basic compounds. These columns provide less retention, better peak shape, and higher efficiency for organic bases than can be obtained on conventional reversed-phase columns.

Supplier: Merck

Tetrabutylammonium hydroxide (TBAOH) is a quaternary ammonium salt,mainly used as a strong base and phase-transfer catalyst.

Supplier: Merck

HPTLC LiChrospher® plates are based on spherical-shaped silica 60 with a particle size of 7 µm, and narrow particle size distribution similar to the phases used in HPLC. LiChrospher® HPTLC plates possess a selectivity that is comparable to respective HPTLC plates, however, plate height and separation numbers are further improved resulting in shorter analysis times.

Supplier: Merck

Clear, colorless fluid polymer useful as a stationary phase in gas chromatography and as an anti-foaming agent.

Supplier: Merck

Silicone oil AS 100 is a viscous liquid used to study the compatibility of segmenting fluids for two phase flow applications in biomedical microdevices.

Supplier: Merck

4-Hydroxy-4-methyl-2-pentanone may be used as an internal standard in the analysis of volatile odor-active compounds present in wine using solid phase extraction with gas chromatography (SPE-GC).

Supplier: Merck

Bisphenol E may be used as a reference standard in the determination of bisphenol E in beverages using on-line solid-phase extraction with fast liquid chromatography coupled with tandem mass spectrometry (on-line SPE fast LC-MS/MS).

Supplier: Merck

AmberChrom™ 1X8 50-100 MESH (CL-) Anion is a strongly basic anion exchange resin which is used as an absorbent in solid phase extraction.

Supplier: Merck

Chromolith® Prep monolithic stationary phases are new ultrapure silica phases which gain their special properties from a bimodal pore structure. This structure is a property of the new 'Sol-Gel' technology and consists of macropores and mesopores. The mesopores with an average diameter of 12 nm, form the fine porous structure of the column interior and create a very large surface area on which adsorption of the target compounds occurs.

Supplier: Merck

Monolinuron CRM may also be used as given below: Determination of 252 pesticides extracted from surface water samples by solid-phase extraction (SPE) using liquid chromatography quadrupole-orbitrap high-resolution tandem mass spectrometry. Extraction of 13 pesticides from four groundwater and three river water samples using silica-based MSU-1 mesoporous solid as a sorbent for their solid-phase extraction (SPE) followed by ultra-performance liquid chromatography-triple quadrupole-mass spectrometric (UHPLC- QqQ-MS/MS) determination. Development and validation of a UHPLC-diode array detection (DAD) method for simultaneous determination of urea and tebuthiuron herbicides in four fresh vegetable samples. Multi-residue analysis of 50 herbicides in 51 grain samples of soybean corn and wheat by ultra-performance liquid chromatography-electrospray ionisation-mass spectrometry (UPLC-ESI-MS). Extraction of 109 pesticide residues from different chemical classes from 345 tomato samples by modified QuEChERS method and their determination using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Simultaneous analysis of 238 pesticides and 78 veterinary drugs in 80 bovine milk samples using ultra-fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS).

Supplier: Merck

Used as a selective enrichment medium for the isolation of Salmonella species from food and environmental specimens.

Supplier: Merck

Ascentis® Silica HPLC columns for the classic use in normal phase HPLC.

Supplier: Merck

Simazine CRM may also be used as given below: Development and validation of an ultrasonic-assisted dispersive liquid-liquid microextraction (UA-DLLME) method for sample extraction followed by gas chromatography-mass spectrometry based determination of endocrine-disrupting herbicides in the river and seawater samples. Determination of triazine pesticide residues in samples of apples pears carrots potatoes tomatoes avocado cucumber spinach bananas and oranges by modified QuEChERS and solid-phase extraction (SPE) procedures followed by liquid chromatography-photodiode array (LC-DAD) analysis. Multi-residue analysis of 67 pesticides in olive oil olives and avocado samples by liquid chromatography-tandem mass spectrometry (LC-MS/MS) to evaluate various clean-up sorbents. Quantitation of 20 pesticides in eel and shrimp samples by a scheduled multiple reaction monitoring (sMRM) method and QuEChERS with EDTA for sample extraction and purification. Analysis of 35 micropollutants including pesticides in water samples by liquid chromatography-tandem mass spectrometry (LC-MS/MS) after their solid-phase extraction. Simultaneous quantification of 58 pharmaceuticals and personal care products (PPCPs) and pesticides in water samples by solvent-based de-emulsification dispersive liquid-liquid microextraction (SD-DLLME) combined with liquid chromatography-tandem mass spectrometry (LCMS/MS).

Supplier: Merck

Purospher® STAR HPLC columns based on highest purity silica are also available for normal phase separations.

Supplier: Merck

Ethyl 4-hydroxybenzoate (ethylparaben) was used to study the in-situ derivatisation solid-phase microextraction procedure for determining parabens, related chlorophenols, and triclosan in water[1].

Supplier: Merck

BIOshell™ 160 Å Peptide CN columns provide an alternative selectivity to the traditional C18 bonded phases.

Supplier: Merck

These phases are used to deactivate the basic compounds. Widely used in industries to analyse the difficult in basic compounds.

Supplier: Merck

All the individual steps associated with solid phase extraction can be carried out using the LiChrolut® extraction unit. This transparent and vacuum-suitable unit, made of glass, can be used to prepare up to 12 samples simultaneously.

Supplier: Merck

Ammonium dihydrogen phosphate 100 g/l in water modifier phosphate modifier for graphite furnace AAS, Supelco®

Supplier: Merck

Magnesium matrix modifier for graphite furnace AAS.

Supplier: Merck

Solid phase extraction vacuum manifolds allow to simultaneously process up to 12 or up to 24 SPE tubes. Precise flow control is provided through each SPE tube by rotating the independent, screw-type valves in the cover, this ensures the packing will not dry out in some tubes while others finish draining.