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Nontargeted Metabolite Profiling in Next-Generation Plant Breeding: A Case Study in Malting BarleyThe power of nontargeted metabolite profiling is illustrated in a study focused on the determination of molecular markers in malting barley that are predictive of desirable malting quality for brewing applications. The metabolite extraction, detection, and analysis methods are highthroughput and reproducible, and therefore, this approach represents a practical addition to the plant breeder’s molecular toolbox.
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A Rapid FT-IR-Based Method for Monitoring Detergent Removal from Biological SamplesIn life science research, detergents are primarily used in sample preparation to liberate cellular components through membrane disruption and to solubilize lipid-associated proteins.
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High-Speed TERS Imaging: The Latest Achievements in nano-Raman SpectroscopyThis article presents developments in tip-enhanced Raman spectroscopy (TERS) that make possible nanoscale imaging of chemical and physical properties of graphene and other carbon species: Innovative integration of technologies brings high-throughput optics and high-resolution scanning for high-speed imaging without interferences between the techniques.
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Comparison of Quadrupole, Time-of-Flight, and Fourier Transform Mass Analyzers for LC-MS Applications (PDF)The authors investigated the analytical capabilities of three types of mass analyzers for liquid chromatography-mass spectrometry (LC-MS) applications, studying the effects of instrument parameters and issues related to sample preparation on the performance of LC-MS analytical methods.
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Using Compact Mass Spectrometry for Detection and Quantitation of Cannibis-Related CompoundsThe transition of cannabis from an illegal drug to a drug for medical and even recreational use raises challenging questions for regulatory agencies and analytical chemists alike. Here, we show a selection of analytical techniques based on compact mass spectrometry in combination with three different sample inlets (atmospheric solids analysis probe), thin-layer chromatography, as well as classical liquid chromatography) for the detection and quantification of cannabinoids and pesticides in cannabis-related material and contraband.
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Detection of Melamine and Other Harmful Food Contaminants Using Gold Nanoparticles, Surface-Enhanced Raman Scattering, and Raster Orbital ScanningMelamine is a dangerous substance when it is used to increase the apparent protein content of food. In this article, the use of novel gold nanoparticles for surface-enhanced Raman spectroscopy (SERS) measurements with raster orbital scanning sampling is described for the detection of melamine and other food contaminants.
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Rapid Quantification of Trypsin Inhibitors in Food and Feed Formulations with Electrospray Ionization Mass SpectrometryA rapid, accurate, and precise method for the quantification of trypsin inhibitor activity was evaluated. The method utilizes alpha hydroxyl acid capped oligo-lysines [hydroxy acid (Lys)n] or alpha hydroxyl acid capped oligo-lysines-methionine [hydroxy acid (Lys-Met)] as substrates. Hydrolysis of the oligopeptides yields unique chemical residues that were readily quantified with electrospray–mass spectrometry (ESI-MS). Accuracy and precision of the approach compared favorably with that of the standard test method.
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Advancements in Molecular Spectroscopy: Instrumentation and ApplicationsHighlights of recent advances in three major areas of molecular spectroscopy: infrared (IR), Raman, and fluorescence.
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High-Speed TERS Imaging: The Latest Achievements in nano-Raman SpectroscopyThis article presents developments in tip-enhanced Raman spectroscopy (TERS) that make possible nanoscale imaging of chemical and physical properties of graphene and other carbon species: Innovative integration of technologies brings high-throughput optics and high-resolution scanning for high-speed imaging without interferences between the techniques.
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Comprehensive Fragrance Profiling of Ginger, Wintergreen, and Rosemary Essential Oils by GC–TOF-MS with Soft Electron IonizationThis article investigates the use of gas chromatography–time-of-flight mass spectrometry (GC–TOF MS) to fragrance-profile three essential oils (ginger, wintergreen and rosemary). As well as considering the compositional differences between the oils, we will examine the use of peak deconvolution to identify closely-eluting compounds, and explore the use of soft electron ionization, assisted by comparison of ion ratios, to discriminate between isomeric monoterpenes that are difficult to identify at conventional 70 eV ionization energies due to their very similar mass spectra.
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New Sample Fractionation Strategies for Proteomic Analyses by LC–MSMass spectrometry has long been a preferred tool for protein identification and biomarker discovery, but preparation of biological samples remains a challenge. Hindrances include the wide range of protein concentrations, sample complexity, and loss or alteration of important proteins due to sample handling. This article describes recent developments in sample fractionation technologies that are overcoming these challenges in interesting ways and are enabling in-depth proteomic studies that were not possible in the past.
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Analysis of Nicotine Alkaloids and Impurities in Liquids for e-Cigarettes by LC–MS, GC–MS, and ICP-MSThe purpose of this study was the development of various analytical MS methods to investigate the chemical composition of e-liquids used in electronic cigarettes and characterize their quality. Low-quality nicotine (the main active compound), glycerol, propylene glycol (solvents), or flavors could greatly increase the toxicity. The search of alkaloid contaminants of nicotine was performed by LC–MS-MS after a deep study of fragmentation pathways by high resolution ESI-MS. A fully validated method for quantitation of organic polar impurities such as cotinine, anabasine, myosmine, nornicotine, and N-nitroso-nornicotine and nicotine itself was developed using MS coupled to UHPLC. To evaluate organic volatile toxicants, headspace from e-cigarette refill liquids was sampled by SPME to perform GC–MS analysis. Finally, heavy metal residues as inorganic toxicants were determined by ICP-MS after simple dilution. A number of cases of contamination by metals (mainly arsenic) was detected.
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High Performance ICP-OES Sample Introduction: How to Choose and Use the Best Nebulizer for Your AnalysisNebulizer selection is a critical but often overlooked aspect of inductively coupled plasma–optical emission spectroscopy (ICP-OES) analyses. There are many different nebulizers available for ICP-OES, and choosing the optimal one can be confusing and difficult. To achieve peak performance from your ICP, it is essential to choose the proper nebulizer based on your sample types in addition to any necessary accessories to maintain long-term performance. In this study, we compare the performance of Glass Expansion’s most popular concentric nebulizer designs for ICP-OES applications as well as a parallel-path nebulizer from another vendor, providing a complete selection guide based on performance and design.
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Rapid Bacterial Diagnostics Via Surface-Enhanced Raman MicroscopySERS of bacterial cells can be a useful technique for clinical diagnostics, as illustrated by the analysis of a human urine sample spiked with urinary tract infection bacteria.
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Analysis of Nicotine Alkaloids and Impurities in Liquids for e-Cigarettes by LC–MS, GC–MS, and ICP-MSThe purpose of this study was the development of various analytical MS methods to investigate the chemical composition of e-liquids used in electronic cigarettes and characterize their quality. Low-quality nicotine (the main active compound), glycerol, propylene glycol (solvents), or flavors could greatly increase the toxicity. The search of alkaloid contaminants of nicotine was performed by LC–MS-MS after a deep study of fragmentation pathways by high resolution ESI-MS. A fully validated method for quantitation of organic polar impurities such as cotinine, anabasine, myosmine, nornicotine, and N-nitroso-nornicotine and nicotine itself was developed using MS coupled to UHPLC. To evaluate organic volatile toxicants, headspace from e-cigarette refill liquids was sampled by SPME to perform GC–MS analysis. Finally, heavy metal residues as inorganic toxicants were determined by ICP-MS after simple dilution. A number of cases of contamination by metals (mainly arsenic) was detected.
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Nonconventional Alternatives to LC–MSAn important attribute of a novel ionization process for use in mass spectrometry (MS) is its simplicity and flexibility to be hyphenated to conventional liquid-based separation methods.
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Rapid and Direct Quantitation of Pharmaceutical Drugs from Urine Using MALDI-MSAn application of MALDI-MS in qualitative and quantitative analysis of pharmaceutical compounds spiked in urine is demonstrated.
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Rapid and Direct Quantitation of Pharmaceutical Drugs from Urine Using MALDI-MSAn application of MALDI-MS in qualitative and quantitative analysis of pharmaceutical compounds spiked in urine is demonstrated.
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Discrimination of Carbonate-Containing and Carbonate-Free Polyvinyl Chloride with Fourier Transform Infrared Microscopy and Raman SpectroscopyA method is presented using IR and Raman microscopy to discriminate carbonate-containing and carbonate-free PVC that helps forensic scientists trace suspects, avoid wrong certificates of authenticity, and characterize and analyze carbonate components.
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Elemental Analysis Through a Plastic BarrierDemonstration of the advantages of using the Orbis micro-XRF elemental analyzer rather than other analysis techniques to perform elemental analysis through a plastic barrier and/or at atmospheric pressure.
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Surface-Enhanced Raman Scattering for Biofilm CharacterizationA summary of the efforts to study microorganism biofilms using surface-enhanced Raman scattering, a powerful technique for in situ analysis of biological molecules and biomolecular organizations
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Discrimination of Carbonate-Containing and Carbonate-Free Polyvinyl Chloride with Fourier Transform Infrared Microscopy and Raman SpectroscopyA method is presented using IR and Raman microscopy to discriminate carbonate-containing and carbonate-free PVC that helps forensic scientists trace suspects, avoid wrong certificates of authenticity, and characterize and analyze carbonate components.
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A Novel Method for Practical Implementation of the Shifted Excitation Raman Difference Spectroscopy (SERDS)SERDS analysis can be easily and successfully carried out using two high-power laser diodes with a fixed-wavelength separation in the presence of high fluorescence.
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Microwave Digestion of Pharmaceutical Finished Products and Ingredients for Upcoming USP Method 233Current USP Method 231 "Heavy Metals" was introduced in 1905 for determining heavy metal impurities in pharmaceutical drug products. The procedures of the method have several limitations, which produce results that are nondiscriminatory, difficult to reproduce, and qualitative, or at best, semi-quantitative.
