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Fast and Flexible Optimization of Modifier Concentrations
Angelika Gratzfeld-Huesgen, Agilent Technologies
Varying buffer or modifier concentrations is frequently done to optimize the separation of compounds. Using the Agilent 1290 Infinity Quaternary Pump with Blend Assist simplifies and accelerates method development. Read More |
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SEC-MALS of Silicones
Wyatt Technology
Polydimethylsiloxane is the world’s most common silicone. Its applications range from contact lenses and medical devices to elastomers, caulking, lubricating oils, and heat resistant tiles. For all of its applications, the weight-average molar mass (and its distributions) is directly associated with the performance of the product. This note shows how Wyatt Technology’s SEC-MALS detectors successfully characterized the samples without resorting to column calibration or reference standards. Read More |
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Measuring Protein Aggregation with the New Viscotek SEC-MALS 20
Malvern Instruments
In this application note, a selection of proteins including BSA, thyroglobulin, and pepsin, are separated using SEC. Absolute molecular weight is measured using the new Viscotek SEC-MALS 20, which clearly indicates the presence of monomers, oligomers, and aggregates in each sample. The results are displayed and discussed. Read More |
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Polynuclear Aromatic Hydrocarbons in Water by Automated Solid Phase Extraction and HPLC Analysis
Lawrence Kramer, FMS, Inc.
Produced as the byproducts of fuel combustion, polynuclear aromatic hydrocarbons (PAHs) consist of fused aromatic rings. As pollutants, they are of concern because some polynuclear compounds have been identified as carcinogenic, mutagenic, and teratogenic. PAHs are lipophilic and therefore found in the environment, primarily in soil, sediment, and oily substances. They also appear in surface and ground water, indicating a source of pollution. This note demonstrates excellent results using a new automated SPE system to prep the samples for HPLC analysis of PAHs. Read More |
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Extraction of synthetic cannabinoids SPICE from oral fluid using ISOLUTE SLE+ 96
Victor Vandell, Biotage AB, Sweden
This application note describes the extraction of a range of SPICE drugs and metabolites from neat oral fluid and oral fluid from a commercial collection kit using ISOLUTE SLE+ in both 96-well plate and column formats, prior to LC–MS–MS analysis. Read More |
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Determination of Benzodiazepines in Hair samples using solid-phase extraction and LC–MS–MS
Jeff Hackett, UCT, Inc.
This methodology details the isolation of commonly prescribed benzodiazepines from hair samples using solid-phase extraction on Clean Screen® DAU columns. After rinsing and drying, the benzodiazepines were eluted using a solution of ammoniacal ethyl acetate. The eluates were dried and dissolved in mobile phase for analysis by LC–MS–MS. Read More |
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Novel Approaches for Small Molecule Identification
Gabriela Zurek, and Aiko Barsch, Bruker Daltonics, Inc.
In plant metabolomics, confirmation of the structure of known compounds and structural elucidation of unknown compounds represents a bottleneck in the analysis of secondary metabolites. In this application note, we present novel tools that facilitate the identification process of natural products when mass spectral libraries are not available and sample amounts are limited. This information can subsequently be used to build well-characterized MS–MS libraries, enabling quick dereplication of known compounds. Read More |
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Quantification of Ginkgo biloba extract by HPTLC
CAMAG Laboratory
Extracts of the leaves of the Ginkgo biloba tree are medicinally used to enhance memory and improve cognition in dementia patients. The quality control which ensures safety and efficacy of the extracts can be based on the analysis of their typical compounds. The presented high performance thin layer chromatography (HPTLC) method is suitable for the quantification of ginkgolide A, ginkgolide B, ginkgolide C, and bilobalide in Ginkgo biloba dry extract. Read More |
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