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A New High-resolution Strong Cation-exchange 1 mm i.d. Column for the Separation of ProteinsThe new 1 mm i.d. ProSwift strong cation-exchange (SCX) column is a polymethacrylate-based monolithic column with sulfonate functionality.
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Reversed-Phase HPLC Column at Extreme High Temperature (150°C or Higher)In general, polymer-based columns have a broad pH range (pH 2 to 13), and some have high temperature tolerance (up to 150°C or higher). Considerably large selectivity changes can be obtained by varying analysis temperature and mobile phase pH. Having control on these two parameters over wide ranges can be especially useful in method development.
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A New High-resolution Strong Cation-exchange 1 mm i.d. Column for the Separation of ProteinsThe new 1 mm i.d. ProSwift strong cation-exchange (SCX) column is a polymethacrylate-based monolithic column with sulfonate functionality.
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Dosing Vehicle Removal in Discovery Phase Pharmacokinetic Studies Using High-Field Asymmetric Waveform Ion Mobility SpectrometryThis article describes the ability to increase the sensitivity for a target compound in the presence of high-level background impurities by removing the dosing vehicle using a high-field asymmetric waveform ion mobility spectrometry gas-phase separation before mass spectrometry analysis.
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High-Throughput Profiling of Long Chain Fatty Acids and Oxylipins by LC–MSLong chain fatty acids (LCFAs) function as a source of metabolic energy, substrates for membrane biogenesis, and storage of metabolic energy. Oxylipins, oxygenated derivatives of LCFAs, regulate the activity of many cellular processes. Existing methods for the analysis of LCFAs and oxylipins have limited compound coverage and sensitivity that, therefore, prevent their application in biological studies. In this work, we developed a high-throughput LC–MS method for analysis of 51 LCFAs and oxylipins. LCFAs and oxylipins were first extracted from biological samples via solid-phase extraction. The extracted molecules were analyzed by targeted comparative metabolomics. Saturated and monounsaturated LCFAs were analyzed in single ion reaction mode, while polyunsaturated LCFAs and oxylipins were analyzed in multiple reaction monitoring mode. Using this method, we successfully quantified 31 LCFAs and oxylipins from mouse livers.
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GSH Conjugate Metabolite Identification with a Hybrid Triple- Quadrupole–Linear Ion-Trap Instrument and Automated Software-Driven Method DevelopmentIn drug discovery, determining information about the extent of metabolism and the elucidation of metabolite structures is a vital step for lead optimization and drug scaffold refinement. The identification and characterization of metabolites plays an important role in both the drug discovery and development phases, as unsuitable pharmacokinetics (bioavailability and drug distribution), toxicity, and adverse drug reactions might be linked to metabolic instability. Historically, metabolite identification was carried out after a compound had been chosen for drug development. However, to reduce candidate failures attributed to toxicity effects, many pharmaceutical companies now conduct these experiments in the earliest phases of candidate drug selection.
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Guard Columns Unleashed: Their Importance in HPLCWebinar Date/Time: Thu, Nov 14, 2024 10:00 AM EST
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Enhancing Mass Spectral Formula Determination by Heuristic RulesA new approach to enhancing the performance of formula identification of true unknowns beyond high mass and spectral accuracy was evaluated. Three heuristic rules on upper limits and ratios of elements were tested for their effectiveness in filtering out false positive formulas with both high- and low-resolution mass spectrometry data. The rule on elements' upper limits was found to be the most effective one in eliminating incorrect formulas.
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Reversed-Phase Enantioselective Chromatography with New µ-mm Chiral Stationary PhasesTo meet the growing need for fast reversed-phase enantiomer separations, two new 3-μm reversed-phase columns, CHIRALCEL® OD® -3R and CHIRALPAK® AD® -3R, have been introduced. High column performance and column stability under a wide range of conditions, including aqueous solvent systems suited to LC–MS, have been
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Comprehensive Screening of Pollutants in Household Dust Using High-Resolution Mass Spectrometry with Enhanced Chromatographic ResolutionHigh resolution time-of-flight mass spectrometry (HR-TOF-MS) with a novel multimode ionization source together with enhanced chromatographic resolution can successfully detect and identify pollutants in household dust samples. Here’s how.
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Novel Sample Preparation Methods for Analyzing Pain Management Drugs in Complex MatricesThe importance of sample preparation for analyzing pain management drugs in different matrices
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Metabolite Identification Using Multiple Mass Defect Filters and Higher Energy Collisional Dissociation on a Hybrid Mass SpectrometerIn this article, the authors evaluate the use of multiple mass defect filters on metabolite identification data from a hybrid mass spectrometer. The study also investigates the use of higher energy collisional dissociation for structural elucidation in metabolite identification experiments.
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A Quality-by-Design Methodology for Rapid LC Method Development, Part IIIThe guest columnists continue their examination of how statistically rigorous QbD principles can be put into practice.
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LC–MS-MS Determination of Malachite Green and Leucomalachite Green in Fish ProductsAlthough not currently used in U.S. or European aquaculture, malachite green (MG) is still an effective and inexpensive fungicide that is used in other countries, particularly in Asia. During metabolism, MG reduces to leucomalachite green (LMG) (Figure 1), which has been shown to accumulate in fatty fish tissues. Trace levels of MG and LMG residues continue to be found in fish products. In a 2005 report, MG was found in 18 out of 27 live eel or eel products imported from China to Hong Kong local market and food outlets, resulting in a government recall and destruction of all remaining products (1).
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Sulfated β-Cyclodextrin as Chiral Mobile Phase Additive for Ultrahigh-Pressure Liquid ChromatographyA fast enantiomeric separation of a chiral aromatic amine was achieved, using ultra high pressure liquid chromatography and highly sulfated β-cyclodextrin (S-β-CD) as a chiral additive in the mobile phase. The stationary phase consisted of a core shell support with a particle size of 2.7 µm. Under these conditions the baseline separation was obtained within 2.5 min. The influence of the concentration of the additive, along with the thermodynamics of the separation, were studied. Molecular mechanics calculations were consistent with the experimental data for the order of elution, providing further evidence of these interactions. The enantiomeric separation at high temperature (90 °C) using only water as mobile phase also was achieved for the first time.
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Fast Analysis of Charge Variants of Monoclonal Antibodies by Ion Exchange ChromatographyDevelopment and production of biopharmaceuticals is a growing segment of the pharmaceutical industry. The development of vaccines is only one - but as a result of the current H1N1 flu hysteria it is the most striking - segment of this emerging field. Recombinant proteins, ranging from insulin products to therapeutic antibodies, represent another important group of biopharmaceuticals. With the introduction of the first so-called biosimilars in Europe the demand for highly efficient analysis methods is further increasing. Newly developed stationary phases for the typical modes of biochromatography of native proteins such as SEC or IEC open up new opportunities for increasing throughput in the bioanalytical lab.
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Structured Approach to Method Development for Bioanalytical HILIC–MS-MS ApplicationsA structured, general purpose approach to method development for bioanalytical hydrophilic interaction chromatography–tandem mass spectrometry (HILIC–MS-MS) applications is described.
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Evaluation of Extraction Methods and Bias Correction by EPA Method 6800 Protocol for Mercury Species in Tuna Fish Tissue Using an Ion Chromatograph Coupled to an ICP–MSMercury pollution mainly originates from industrial activities such as chlorine production, garbage incineration and above all coal-fueled power generation. The US Environmental Protection Agency (US EPA) considers mercury as highly toxic with a pronounced accumulative and persistent character.
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Online Automated SPE–LC–MS-MS Quantitation of Sulfonamide Antibiotics and Pesticides in Surface Waters Using a Triple-Quadrupole Mass Spectrometer and Electrospray Ionization ProbeThis article describes a fully automated online solid-phase extraction–liquid chromatography–tandem mass spectrometry (SPE–LC–MS-MS) setup using a mass spectrometer and an electrospray ionization probe for analyzing different groups of polar contaminants in natural waters. The goal was to develop an online SPE method for the quantification of sulfonamide antibiotics, including their acetyl metabolites, as well as for frequently used pesticides (triketones, phenylureas, chloracetanilides, phenoxyacetic acids, amides, and triazines) in ambient waters. The analytical methods were applied successfully for a field study in an agricultural region within the catchment area of Lake Greifensee near Zurich, Switzerland.
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Tips & Tricks: Treating Your GPC/SEC System ProperlyThis installment of Tips & Tricks will provide some helpful pointers to keep your GPC/SEC system in good shape.
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Automated Extraction Technique for Improved Recovery of PhenolsDionex has developed a new standard for flow-through solvent extraction which allows accelerated solvent extraction (ASE®) of matrices that have undergone acid or alkaline pretreatment or digestion. The new ASE 150 and ASE 350 systems use extraction cells and post-cell solvent pathways constructed of Dionium™ material. This pH-hardened substance resists corrosion under acidic or alkaline conditions used in standard pretreatments, widening the scope of ASE applications and significantly expanding its capabilities.
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Metabolite Identification Using Multiple Mass Defect Filters and Higher Energy Collisional Dissociation on a Hybrid Mass SpectrometerIn this article, the authors evaluate the use of multiple mass defect filters on metabolite identification data from a hybrid mass spectrometer. The study also investigates the use of higher energy collisional dissociation for structural elucidation in metabolite identification experiments.
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Dynamic Extraction: A High-Speed, High-Capacity Purification Process That is Rapidly ScalableThe authors discuss a preparative process using the principles of countercurrent chromatography. This process is faster, capable of loadings from milligrams to hundreds of grams, and uses robust equipment.
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ICP MS Detection for HPLC Analyses of Pharmaceutical ProductsThe authors investigate applications for ICP-MS detection with reversed-phase HPLC.
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Facilitating Discovery of Prion Disease Biomarkers by Quantitative GlycoproteomicsThe authors examine MS-based methods to search for protein biomarkers of prion diseases from plasma samples.
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Chemical Warfare Agent Spectral Imaging for Real-Time Identification and LocalizationIn this article, the authors discuss the need for protection against chemical attacks and the role of passive imaging spectroradiometers in the detection of remote chemical agents.
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ICP MS Detection for HPLC Analyses of Pharmaceutical ProductsThe authors investigate applications for ICP-MS detection with reversed-phase HPLC.
