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“Truly Natural”: Fully Automated Stir-Bar Sorptive Extraction with Enantioselective GC–MS Quantitation of Chiral Markers of Peach AromaA simple, automated, and fast method to quantify complex odorants in foods is described using stir-bar sorptive extraction (SBSE) combined with fast enantioselective GC–MS analysis. The total analytical method takes only 30 minutes and does not require any sample pretreatment.
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A Hydrophilic Interaction Chromatography Method for the Purity Analysis of CytosineCytosine (chemical name 4-amino-2-hydroxypyrimidine) is a pyrimidine derivative with a hetereocyclic aromatic ring and two substituents (amine and keto groups) attached and is a polar compound of significant biological and pharmaceutical interest. In response to the intended use of bulk cytosine as a raw material in pharmaceutical manufacturing, a method for the determination of the purity of cytosine was developed.
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Tackle Method 625.1 with Superior EvaporationSee the advantage in optimizing your solvent evaporation for maximum accuracy and precision to comply with U.S. EPA Method 625.1
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Kurt Grob — One of the Fathers of Capillary GCIn this month's installment, Kurt Grob's life and achievements are described by someone who knew him like few other people did: his son, Koni Grob.
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Recent Advances in Ultrahigh-Pressure Liquid ChromatographyUltrahigh-pressure liquid chromatography (UHPLC) is a technique that is experiencing continued growth due to the benefits in separation power and speed of analysis over traditional HPLC. We attempt here to give an overview of some of the advances that have occurred in UHPLC since 2003, from the standpoint of both fundamental research and the introduction of commercially-available technology.
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Interaction of Dichloromethane Solvent with n-Alkylamines Analyzed by Electron Ionization GC–MSThe analysis of amines by gas chromatograph ;mass spectrometry (GC–MS) using electron ionization (EI) has always been a challenge
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Optimization Approaches in the Routine Analysis of Monoclonal Anitbodies by Capillary ElectrophoresisElectrophoretic techniques, such as sodium dodecyl sulphate polyacrylamide (SDS-PAGE) and isoelectric focusing (IEF) gels, have traditionally been part of release testing in the biopharmaceutical industry. However, these slab gel methods are inconvenient and irreproducible because of the staining/destaining steps used in analyte detection, the use of toxic reagents and high intra- and inter-gel effective mobility variability.
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The Misunderstood Laboratory Solvent: Reagent Water for HPLCA good pretreatment system combines reverse osmosis and electrodeionization technologies.
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Microemulsion HPLCMicroemulsion-based HPLC (MELC) is a recent development offering reduced sample preparation times for complex samples and generic separation conditions applicable to a wide range of solutes. This article introduces the concepts of MELC and discusses the possible benefits and future applications.
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Using pH-LC to Control Selectivity of Acidic and Basic Compounds on Gemini-NXThe use of mobile phase pH to control analyte ionization states (pH-LCâ„¢) in reversed phase HPLC separations is a highly effective way to change selectivity. The ionized species of an analyte is shown to have higher polarity (less hydrophobicity) than the neutral species, which results in a loss of expected retention for that analyte. This can be attributed to less interaction with the hydrophobic stationary phase and greater affinity with the aqueous portion of the mobile phase. Ionized species also participate in ionic interactions with exposed and activated silanols, which impact peak shape and reproducibility.
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Synthetic Fused Silica Capillary Tubing: A Discussion of DiffusionSynthetic fused silica capillary tubing is commonly used as the preferred substrate for chromatographic separation columns. In limited instances the absorption and diffusion of molecules into and through the fused silica deserves consideration.
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Quantitative Analysis of Carbonyl-DNPH Derivatives by UHPLC–UVThermo Fisher Scientific Application Note
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LC–API-MS(/MS) for Biological Samples: Importance of Hydrophobicity, Molecular Weight and Structural DevelopmentThe combination of reversed-phase high performance liquid chromatography (RP-HPLC), atmospheric pressure ionization (API), mass spectrometry (MS) and tandem mass spectrometry (MS/MS) is ideal for determining and characterizing analytes in complex biological matrices. This review looks at the importance of parameters such as hydrophobicity, ionization properties, molecular mass and, partially, the molecular structure resulting from applied LC–MS–MS systems in analytical laboratories. The use of these parameters to investigate biomolecules and their unambiguous identification is also described.
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Monolithic Stationary Phases for HPLC and Sample PreparationMonoliths are separation media in the format that can be compared to a single large "particle" that does not contain interparticular voids. As a result, all the mobile phase must flow through the stationary phase. This convective flow greatly accelerates the rate of mass transfer. In contrast to diffusion, which is the typical driving force for mass transfer within the pores of particulate stationary phases during chromatographic processes, convective flow through the pores enables a substantial increase in the speed of the separation of large molecules such as proteins. A thorough theoretical treatment of the mass transfer within monolithic materials has been developed by Liapis (1) and Tallarek (2).
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Application of a GPC-LC–MS/MS Method for the Determination of 31 Mycotoxins in Edible OIlsGel Permeation Chromatography (GPC) is widely used for sample clean up in mycotoxin analysis. The most commonly described methods use GPC columns packed with SX-3 BioBeads suitable for cleaning Zearalenone, Aflatoxins, and Trichothesenes from edible oils and fatty matrices. Separation of Fumonisins from the oil fraction are inadequate with this column.
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In Bruges: HPLC 2025The 54th International Symposium on High Performance Liquid Phase Separations and Related Techniques (HPLC 2025) will be held from Sunday through Thursday, June 15-19, 2025, in Bruges, Belgium.
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Rapid Screening of Pesticides Using U-HPLC/MSThe screening of pesticides, mycotoxins, and veterinary drugs is of great importance in regulated environments such as food or feed analysis. Due to some of the limitations of traditional triple quadrupole approaches (for example, targeted analyte detection, limited number of compounds, and unidentified unknown compounds), there is currently a trend towards use of full-scan MS data for the analysis of residue samples. Current screening approaches mainly rely on the use of ToF instruments coupled to U-HPLC delivering mass accuracy (~5 ppm) at a maximum resolution of <15,000. This can produce inaccurate mass measurements due the presence of unresolved background matrix interferences. In this work we show a full-scan MS screening approach with the Thermo Scientific Exactive mass spectrometer, a novel single-stage Orbitrapâ„¢ MS capable of providing precise mass accuracies at resolutions of up to 100,000 without the need for internal mass calibration.
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The Role of Triple Quadrupole GC–MS in Steroid AnalysisThe authors discuss the use of GC-MS in drug doping testing.
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Fast, Single-Run Analysis of Polybrominated Diphenyl Ethers (PBDEs), Including Decabromodiphenyl (BDE-209)This article addresses the contribution of thermal stability and column activity to BDE-209 breakdown and also describes an optimized method that resolves BDE-209 and other important congeners.
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Melamine and Cyanuric Acid Detection in 5 Min Using LC–MSSince September 2008, 294,000 infants and young children suffered urinary problems due to the contamination of melamine in infant milk powder and were hospitalized. This hospitalization was required to treat the symptoms caused by the ingestion of melamine contaminated infant formula and related dairy products. Previously in 2007, pet food, animal feed, wheat gluten, and other protein-based foods were found to contain residues of melamine and its degradation product cyanuric acid (2).
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Hardware and Software Challenges for the Near Future: Structure Elucidation Concepts via Hyphenated Chromatographic TechniquesThis month, guest columnists Kind and Fiehn discuss small-molecule structure elucidation (excluding peptides) using hyphenated chromatographic techniques, mass spectrometers, and other spectroscopic detectors.
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Application of a GPC-LC–MS/MS Method for the Determination of 31 Mycotoxins in Edible OIlsGel Permeation Chromatography (GPC) is widely used for sample clean up in mycotoxin analysis. The most commonly described methods use GPC columns packed with SX-3 BioBeads suitable for cleaning Zearalenone, Aflatoxins, and Trichothesenes from edible oils and fatty matrices. Separation of Fumonisins from the oil fraction are inadequate with this column.
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Removal of Endogenous Matrix Components Using EVOLUTE® CX Mixed-Mode Cation Exchange Solid Phase ExtractionSample preparation is an essential technique to remove unwanted matrix components prior to LC–MS-MS analysis of drugs in biological fluids. Plasma matrix components whether endogenous (salts, proteins, and phospholipids) or exogenous (dosing vehicles, e.g. PEG 400), can interfere with compounds of interest leading to regions of ion suppression or enhancement. This can lead to inaccurate quantitation and have adverse effects on sensitivity. Mixed-mode SPE provides cleaner extracts as a result of rigorous interference wash steps, afforded by the dual retention mechanism of the sorbents.
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How Advances in LC/LC–MS Enable Better Characterization of mRNA TherapeuticsA review of advances in mRNA analysis using LC and LC–MS.
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LC–MS-MS Analysis of Malachite Green, Leucomalachite Green, Ciprofloxacin, and Tetracycline in Food Samples Using an Online TurboFlow LC–MS MethodThe analysis of chemical residues in food requires techniques sensitive enough to detect and quantify contaminants at or below the maximum residue limit (MRL) of the compound in a given sample matrix. Because of increased food safety regulations and the growing numbers of samples to be analyzed, it is critical that the analytical techniques provide high sample throughput.
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The Analysis of Semivolatile Compounds in Environmental and Crude Vegetable Extracts by Ion-Trap Mass SpectrometryToday's ion traps use advanced scanning techniques such as automatic gain control, axial modulation, and triple resonance scanning, resulting in efficient control of both ionization and optimal storage of ions in the trap during analysis. These instruments provide excellent sensitivity and quantitative data, even in "dirty" samples.
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The Separation of Enantiomers on Modified Cyclodextrins by Capillary Electrochromatography (CEC)Various modes of capillary electrochromatography (CEC) for the separation of enantiomers on immobilized cyclodextrin derivatives are described. The following techniques have been used: (i) open-tubular electrochromatography (o-CEC), (ii) packed electrochromatography (p-CEC) and (iii) monolithic electrochromatography (rod-CEC). Three different strategies to prepare enantioselective cyclodextrin-coated chiral monoliths are described. The advantages and disadvantages of the various methods are outlined.
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Determination of PAHs in Combustion-Related Samples via Multidimensional Chromatographic MethodsGas chromatography–mass spectrometry (GC–MS), reversed-phase LC with stop-flow fluorescence (FL), and constant energy synchronous fluorescence spectroscopy (CESFS) are explored to determine PAH isomers in three combustion-related standard reference materials.
