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Hydrogen Deuterium Exchange Mass Spectrometry: An Emerging Biophysical Tool for Probing Protein Behaviour and Higher-Order StructureThis article looks at how hydrogen-deuterium exchange mass spectrometry (HDX-MS), an MS-based labelling approach, has begun to serve as a means for performing routine biophysical analysis.
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BTEX Determination in Gasoline Containing Ethanol by Single Oven MDGCThe determination of BTEX in gasoline is usually performed in accordance with the standard test method ASTM D3606 using gas chromatography. However, particularly in the presence of ethanol, co-elutions are observed in one-dimensional chromatography. In this application note a method is described applying multidimensional GC to overcome the separation problem.
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Novel Analytical Methods for the Discovery and Trace Analysis of Biochemically Active CompoundsNovel analytical methods for the discovery and trace analysis of biochemically active compunds in three main area are described: protein analysis, screening technologies and multidimensional separations.
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A Simple Instrumental Approach for "Supercritical" Fluid Chromatography in Drug Discovery and Its Consequences on Coupling with Mass Spectrometric and Light Scattering DetectionA simple experimental setup applied in a drug discovery laboratory illustrates some anomalies and misconceptions about supercritical fluid chromatography for drug discovery.
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Liquid Chromatography–Time-of-Flight Mass Spectrometry for Cannabinoid Profiling and Quantitation in Hemp Oil ExtractsA primary impediment to cannabinoid research is the fact that materials possessing psychoactive Δ-9-tetrathydrocannabinol are considered Schedule I drugs as defined in the U.S. Controlled Substances Act. An alternative source of cannabinoids may be found in hemp oil extracts. Hemp contains a low percentage of Δ-9-tetrathydrocannabinol (THC) by weight but relatively high amounts of non-psychoactive cannabinoids. The liquid chromatography-time of flight mass spectrometry (LC-TOF) method presented herein allows for the accurate, precise and robust speciation, profiling and quantification of cannabinoids in hemp oil extracts and commercial cannabinoid products for research and development laboratories. The method was determined to chromatographically separate 11 cannabinoids including differentiation of Δ-8-tetrahdrocannabinol and THC with excellent linear dynamic range, specificity and sensitivity.
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Electrochemistry and LC–MS for Metabolite Generation and Identification: Tools, Technologies and TrendsThis article provides an introduction to electrochemical liquid chromatography mass spectrometry. The instrumental set-up is presented and selected applications in drug development processes are discussed.
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Novel Analytical Methods for the Discovery and Trace Analysis of Biochemically Active CompoundsNovel analytical methods for the discovery and trace analysis of biochemically active compunds in three main area are described: protein analysis, screening technologies and multidimensional separations.
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Application of Microbore UHPLC–MS-MS to the Quantitation of In Vivo Pharmacokinetic Study SamplesLiquid chromatography coupled with tandem mass spectrometry (LC–MS-MS) is the primary bioanalytical technique used today within the pharmaceutical industry for the quantitation of small molecules in biological matrices such as plasma. In recent years, chromatographic resolution has been improved with the development of ultrahigh-pressure liquid chromatography (UHPLC) systems that utilize smaller diameter particles (< 3 μm) and operate at pressures > 5000 psi. While most LC systems utilized for this application are optimized for columns with internal diameters (i.d.) between 2.0 and 4.6 mm, a new UHPLC system designed for microbore columns (≤ 1 mm i.d.) has been introduced recently. This article will discuss the advantages of using a microbore UHPLC system coupled with a tandem mass spectrometer for the quantitation of in vivo pharmacokinetic samples. These advantages include reduced sample and solvent consumption, improved chromatographic resolution and speed, and reduced mass spectrometer source..
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LCGC and Its Readers: 30 Years StrongLCGC's global online presence is an ever-growing aspect of this publication as we strive to bring our readers the knowledge they need in a timely manner.
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Analysis of PCBs in Food and Biological Samples Using GC Triple Quadrupole GC–MS–MSPolychlorinated biphenyls (PCBs) are a class of extremely persistent industrial chemicals manufactured for use in electrical transformers, capacitors, inks, paints, pesticides, dust control or insulating fluids. Estimates have put the total global production of PCBs on the order of 1.5 million tons.
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Determination of 25-mono-hydroxy-vitamin D2 and D3 in Human Plasma Using a Symbiosis Pico System: ACN Free On-line SPE-LC–MS–MSSpark Holland Application Note
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Mass Information on Charge Variants in Minutes, Not WeeksExplore how an integrated, single platform imaged capillary isoelectric focusing (icIEF)-UV/MS workflow with the Intabio ZT system aims to tackle the challenge of charge heterogeneity profiling with a disruptive strategy that allows for separation, quantitation, and identification of individual charge variants to be achieved in minutes on a single platform.
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30-s UHPLC Separation of Pharmaceutical Ingredients using PDA DetectionUltra fast separations of acetaminophen, caffeine, propofol and parabens are achieved in 30 s using the Thermo Scientific Accela UHPLC system with the 80 Hz PDA detector. The performance of the Accela PDA detector is highlighted by its low noise level, low drift, four orders of magnitude linear working range and high sensitivity.
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Identification of Psychotropic Substances in Mushrooms by UHPLC/MSForensic laboratories face a daunting task to identify trace amounts of controlled substances in small samples of seized evidence. Unambiguous identification is required to meet the stiff challenge that is sure to be raised in the courtroom. Positive proof is especially difficult to establish if the controlled substance is hidden in a complex food matrix with a high content of sugars, fats, fatty acids, proteins, and alkaloids.
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The Advantages of Hollow Fibre FFF (HF5) with Asymmetrical Flow FFF (AF4)The functional principles of AF4 and HF5 are discussed.
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Quantitation and Characterization of Copper Plating Bath Additives by Liquid Chromatography with Charged Aerosol Detection and Electrochemical DetectionA novel approach is described for the quantitation of three additives typically used in copper plating using a dual LC system with an ECD and a CAD.
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Synthesis and Applications of BEH Particles in Liquid ChromatographyHow ethylene-bridged hybrid inorganic–organic (BEH) particles are prepared and how their special qualities can be used to improve separations
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Rapid Analysis of Pesticides in Difficult Matrices Using GC–MS–MSPesticides are widely used in agriculture to protect crops and to improve efficiency of production. Consequently, governments, food producers and food retailers have a duty to ensure that any residues occurring in foods for human consumption are at or below statutory maximum residue levels (MRLs). Regulation EC 396/2005 adopted in the European Union sets MRLs for more than 500 different pesticides in over 300 different food commodities.
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A Comparative Study on the Purification of Library Compounds in Drug Discovery Using Mass-Directed Preparative SFC and Preparative RPLCIn the past decade, supercritical fluid chromatography (SFC) has experienced a steady growth in acceptance, particularly in pharmaceutical and chemical laboratories. In SFC, "supercritical" CO2 combined with one or more polar organic solvents, most commonly alcohols, are used as mobile phase. Preparative SFC is deemed by many to hold the greatest promise to attain mainstream acceptance. The reduction in solvent consumption and collection in relatively small volumes of volatile organic solvents, hence, a much less stringent post-purification endeavour, lead to significant savings on operation costs. For example, Ripka et al. calculated that 20000 samples purified by SFC instead of reverse phase liquid chromatography (RPLC) would realize a 48 times reduction in solvent consumption.1
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The Unique Selectivity of π-Interactions for Solid-Phase ExtractionHypercrosslinked polystyrene-type (solid-phase extraction) SPE materials exhibit a unique ability to enter p-interactions with aromatic, heterocyclic and unsaturated compounds. This property permits selective extraction and pre-concentration of the above classes of species from non-polar media and fatty matrices. The principle has been exploited for developing analytical protocols to determine polar furan derivatives in mineral transformer oil, polyaromatic hydrocarbons (PAHs) in smoked fish and for the fractionation of polychlorinated aromatic compounds in environmental matrices.
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Gas Chromatography with Soft Ionization Mass Spectrometry for the Characterization of Natural ProductsThe application of gas chromatography (GC) combined with atmospheric pressure chemical ionization mass spectrometry (GC–APCI-MS) and with supersonic molecular beam ionization mass spectrometry (GC–SMB-MS).
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The Nomenclature of Comprehensive Two-Dimensional Gas Chromatography: Defining the Modulation Ratio (MR)The interpretation of comprehensive two-dimensional gas chromatography (GCÃ-GC) based on the modulation ratio (MR) concept encompasses method implementation, ideas on quantitative measurement and how modulation phase affects GCÃ-GC.
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GCxGC-FID for Qualitative and Quantitative Analysis of PerfumesExploring the use of GCxGC-FID as a technique for qualitative and quantitative analysis of perfumes
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A Modular Approach to Pressurized Liquid Extraction with In-Cell CleanupA modification of the popular PLE technique is discussed.
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UHPLC Coupled with Fourier Transform Orbitrap for Residue AnalysisThe trend in residue analysis has changed from target-oriented procedures towards accurate mass full-scan MS techniques. This article describes these developments and addresses the implications of 2002/657/EC.
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Chiral Purification with Stacked Injections and Collections Using the Prep 100 SFC MS Directed SystemChiral chromatography has become the preferred tool for enantiomer separations in the early stages of pharmaceutical development for the purpose of accurately identifying single pure enantiomers with pharmacologic, toxicological, and clinical information, as stipulated by the FDA.1
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Therapeutic Diazepam Monitoring in Human Plasma and Urine by HPLC: An Application for AlcoholismA rapid and simple high performance liquid chromatography (HPLC) method with basic extraction assays was developed to investigate free diazepam levels in the plasma and urine samples of patients medicated with this drug for the management of alcohol withdrawal syndrome. The HPLC analysis was optimized and evaluated for linearity, imprecision, recovery, detection and quantification limits. The method showed linearity between 50–500 ng/mL (r2 ≥ 0.990). Coefficients of variations (%CV) were calculated to be in the range of 1.77–9.60. According to ICH guidelines, theoretical limits of detection (LOD) and quantification (LOQ) for plasma and urine were calculated as 8.3 ng/mL, 27.5 ng/mL and 8.2 ng/mL, 26 ng/mL respectively. Diazepam monitoring in plasma and urine displayed remarkable variations. The importance of adjusting doses according to individual requirements and the routine monitoring of plasma or urine for patients under medication is highlighted.
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BTEX Determination in Gasoline Containing Ethanol by Single Oven MDGCThe determination of BTEX in gasoline is usually performed in accordance with the standard test method ASTM D3606 using gas chromatography. However, particularly in the presence of ethanol, co-elutions are observed in one-dimensional chromatography. In this application note a method is described applying multidimensional GC to overcome the separation problem.
