Author
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Enhanced Peptide Identification with an Ultra High Resolution Mass SpectrometerAnalysis of biological samples frequently involves the identification of peptides from low amounts of complex samples. Confident identification of these peptides requires rapid generation of high quality, high sensitivity MS and MS–MS data. The maXis TOF mass spectrometer incorporates novel technical innovations, which together produce an unprecedented level of data quality, resulting in a significant increase in the number of peptides identified from challenging samples.
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Rapid LC Determination of UV Filters in Cosmetics using Ethanol as the Mobile PhaseA rapid and environmentally friendly LC method for the simultaneous determination of 12 UV filters in cosmetic samples using ethanol as the mobile phase.
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Stability and Recovery Influences of Benzo[a]pyrene, Benzo[a]anthracene, Benzo[b]fluoranthene, and Chrysene during Sample Preparation of Plant MatricesQuantification of European Union (EU)-priority polycyclic aromatic hydrocarbons (PAHs) in plant matrices is a crucial task. Various methods for enrichment and preconcentration, such as the preloaded-pipette tip solid‑phase extraction (SPE) (1), are available. Nevertheless, analyte recovery as a result of homogenization, sample preparation, and extraction are rarely discussed in the field of phytopharmacy. This study deals with the recovery in dry plant extracts, which are typically used in phytopharmaceuticals and reflect the actual polycyclic aromatic hydrocarbon content in the commercially available end product (2). The aim of this study was to monitor benzo[a]pyrene, benzo[a]anthracene, chrysene, and benzo[b]fluoranthene loss of spiked samples as a result of commonly-used sample pretreatment, extraction, filtering, and evaporating techniques in 1:1 (v/v) cyclohexane–ethyl acetate primulae flos and sambuci flos dry extracts. Results showed that improper sample preparation can lead to false results. In the case of benzo[a]pyrene with a deviation of 155% from the theoretical true value.
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Using Comprehensive GCxGC–TOF-MS for Enhanced Detection and Separation in Antidoping Control ScreeningThe misuse of androgenic anabolic steroids in sports was banned in 1976 by the International Olympic Committee and global sports community. The illegal use of anabolic steroids has reached disturbing levels worldwide. This worldwide problem is fueled partially by an ever-increasing demand for better athletic performance. The World Anti-Doping Agency has formulated strict guidelines for minimum allowable concentrations of exogenous anabolic steroids and their metabolites. The standard test methods for doping control are analyzed in urine samples with trimethyl-silyl derivatization. Urine is a complex and difficult biological matrix. This research shows the advantages of using comprehensive two-dimensional gas chromatography–time-of-flight-mass spectrometry (GCÃ-GC–TOF-MS) and illustrates the capability of GCÃ-GC-TOF-MS to be an effective instrumental option for antidoping control screening.
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Stability and Recovery Influences of Benzo[a]pyrene, Benzo[a]anthracene, Benzo[b]fluoranthene, and Chrysene during Sample Preparation of Plant MatricesQuantification of European Union (EU)-priority polycyclic aromatic hydrocarbons (PAHs) in plant matrices is a crucial task. Various methods for enrichment and preconcentration, such as the preloaded-pipette tip solid‑phase extraction (SPE) (1), are available. Nevertheless, analyte recovery as a result of homogenization, sample preparation, and extraction are rarely discussed in the field of phytopharmacy. This study deals with the recovery in dry plant extracts, which are typically used in phytopharmaceuticals and reflect the actual polycyclic aromatic hydrocarbon content in the commercially available end product (2). The aim of this study was to monitor benzo[a]pyrene, benzo[a]anthracene, chrysene, and benzo[b]fluoranthene loss of spiked samples as a result of commonly-used sample pretreatment, extraction, filtering, and evaporating techniques in 1:1 (v/v) cyclohexane–ethyl acetate primulae flos and sambuci flos dry extracts. Results showed that improper sample preparation can lead to false results. In the case of benzo[a]pyrene with a deviation of 155% from the theoretical true value.
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Simultaneous Determination of Formononentin, Biochanin A, Daidzen and Genistein in Trifolium pratense (Red Clover) by HPLCA simple and rapid HPLC method was established to simultaneously determine the active ingredients of red clover.
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Automated Gas and Liquid Chromatography Retention Time Modelling and Prediction Using Open-Access Molecular Database Structures and Quantitative Structure-Chromatography Retention RelationshipsThis article describes open access sofware for the modelling and prediction of retention times in gas and liquid chromatography. This software provides useful results for food analysis.
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Monday Tutorial SessionsThe tutorial sessions at HPLC 2018 are part of the conference’s educational mission. The sessions consist of presentations given by experts on various topics, with more background provided than might be presented in a typical 20-minute talk.
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New Horizons in Reversed-Phase ChromatographyThe coauthors discuss the various attributes of and approaches to reversed-phase chromatography.
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Toward a Universal Detector for Small Molecule Applications: Direct-EI in LC–MSThis article describes the operating principles of the direct-electron ionization (EI) interface, which is becoming more popular in many LC–MS applications. Matrix effects and the role of direct-EI as a universal detector for small molecule analysis are also discussed in detail. The advantages and drawbacks of this approach are described and a comparison with atmospheric pressure ionization (API) interfaces is made. The potential of direct-EI is illustrated with a selection of practical applications.
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TSKgel Amide-80, 2 m Columns for the Analysis of GlycansMost proteins, particularly soluble and membrane-bound proteins expressed in the endoplasmic reticulum, are glycosylated. The extent and result of glycosylation varies.
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Advances in TOF-MS-Based Screening for Food Safety Residue Analysis with a Positive ApproachMass spectrometry plays an increasingly significant role in the analysis of residues and contaminants in food. Here we will illustrate how the combination of ultrahigh-pressure liquid chromatography (UHPLC) and high-resolution time-of-flight-mass spectrometry (TOF-MS) is used to generate a screen of veterinary drug residues in products of animal origin. The use of UHPLC–TOF-MS and dedicated, workflow directed software allows rapid screening for large numbers of residues and automated quantification of positive samples. In addition, we illustrate how the data generated using MSE acquisition mode enable critical structural information to be collected, which offers additional selectivity and confirmatory data for compound identification and facilitates elucidation of the structure of newly discovered compounds.
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Revisiting the Fundamentals of Untargeted Data Analysis with Comprehensive Two-Dimensional Gas Chromatography (GC×GC): With Great Peak Capacity, There Must Also Come Great ResponsibilityTwo-dimensional gas chromatography (GC×GC) and chemometrics are leading the way in new strategies on multivariate data analysis. Using GC×GC in untargeted analysis reveals how far the technique has advanced the field of separation science.
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Ultralow Detection of Estrogenic Compounds by GC–NCI-MS-MSA number of clinical situations now call for high-sensitivity measurement of estrogens, including monitoring during female hormone replacement therapy, antiestrogen treatment, and estrogen deficiency in men. Traditional immunoassay methods and liquid chromatography–tandem mass spectrometry (LC–MS-MS) do not provide the sensitivity and selectivity required for these applications. In contrast, a gas chromatography–negative chemical ionization–tandem mass spectrometry (GC–NCI-MS-MS) platform can provide detection limits below 1 pg/mL when used in conjunction with the appropriate derivatization protocol, with very short cycle times.
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Advances in Multidimensional LC–GC for Food AnalysisOn-line heart-cut LC–GC and, more recently, comprehensive LC–GC (LC?GC) are very powerful analytical techniques because of the combination of the selectivity features of LC with the high efficiency of GC. This article presents an overview of the most recently used interfacing systems, as well as applications in the food analysis.
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Analysis of Barbiturates in Urine with Agilent 6430 LC–MS–MS and Poroshell 120 EC-C18Toxicology Laboratory at the Veterans Administration, Portland, Oregon, USA, Agilent Technologies
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Peptide Analysis: Zwitterionic Chiral Ion-Exchangers as Complementary Option to HILIC and to Reversed-Phase ChromatographyTherapeutic peptides represent one of the fastest growing segments in the pharmaceutical market. To bring these products to the market in a consistent manner, high quality is a major concern and requires stringent quality control (QC) methods. This article discusses the potential of zwitterionic chiral ion-exchangers to support peptide analysis and quality control as a flexible complementary tool to monitor the stereochemical integrity and chemical modifications.
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Country Focus: Pole PositionsDoug Kitson looks at some of Poland's leading separation science groups.
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Next Generation Peak Fitting for SeparationsSeparation scientists frequently encounter critical pairs that are difficult to separate in a complex mixture. To save time and expensive solvents, an effective alternative to conventional screening protocols or mathematical peak width reduction is called iterative curve fitting.
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Laser Thermal Desorption and GC×GC for Harsh Environment and Planetary Mass SpectrometryThe development of analytical instrumentation for harsh terrestrial environments and outer planet space exploration exponentially increases instrument requirements-for features such as robustness, autonomous operation, and speed-and poses unique system integration challenges. Here, we explore the use of laser thermal desorption coupled to comprehensive two-dimensional gas chromatography (LTD-GC×GC) for use with a compact, high-resolution mass spectrometer for challenging applications.
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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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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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Nontargeted Screening and Accurate Mass Confirmation of Pesticides Using High-Resolution LC–Orbital Trap Mass SpectrometryThe increasing use of pesticide testing coupled with reductions in maximum permissible residue levels of pesticides in food have driven demand for fast, sensitive, and cost-effective analytical methods for high-throughput screening of multiclass pesticides in food. Detection of 510 pesticides at low parts-per-billion levels can be achieved within minutes using orbital trap technology. The high resolving power of these systems enables accurate mass confirmation of all compounds, including isobaric pesticides. This article will provide an overview of current legislation and illustrate how mass spectrometry instrumentation can enable fast and accurate pesticide screening.
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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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Nontargeted Screening and Accurate Mass Confirmation of Pesticides Using High-Resolution LC–Orbital Trap Mass SpectrometryThe increasing use of pesticide testing coupled with reductions in maximum permissible residue levels of pesticides in food have driven demand for fast, sensitive, and cost-effective analytical methods for high-throughput screening of multiclass pesticides in food. Detection of 510 pesticides at low parts-per-billion levels can be achieved within minutes using orbital trap technology. The high resolving power of these systems enables accurate mass confirmation of all compounds, including isobaric pesticides. This article will provide an overview of current legislation and illustrate how mass spectrometry instrumentation can enable fast and accurate pesticide screening.
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Optimization of Asymmetrical Flow Field-Flow FractionationThis article illustrates how to choose the best experimental parameters for asymmetrical flow field-flow fractionation.
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Data Handling and Validation in Automated Detection of Food Toxicants Using Full Scan GC–MS and LC–MSAn overview of current chromatography-based food toxicant screening is presented.
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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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Quantitative Proteomic Workflow for Discovery of Early Rejection Kidney Transplant Peptide Biomarkers and Subsequent Development of SRM Assays in UrineThe accurate diagnosis of renal allograft rejection currently depends upon a biopsy. Transplant medicine would benefit greatly from the availability of noninvasive tests for early detection of rejection and immunosuppressive drug therapeutic monitoring. Only a limited number of studies have been published to date on specific proteins associated with allograft rejection. Typically, renal dysfunction due to humoral transplant rejection or other pathologies results in the increase of protein excreted in urine (1–5). In blood, endogenous peptides (not generated by trypsin digestion ex vivo) are likely candidate biomarkers for many diseases and pathologies as they are secreted from tissues and enter the bloodstream (6,7). The analysis of endogenous protein and peptide fragments in urine can provide a noninvasive, early indication of kidney transplant rejection or disease.
