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A Convenient Alternative to MALDI and ESIAs was demonstrated by ESI and MALDI, and, more recently, ambient ionization approaches, successful new ionization methods can have an enormous impact on science. Novel ionization processes, such as inlet and vacuum ionization, are some of the latest of these approaches, and provide excellent alternatives to traditional approaches.
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Determination of Low Levels of Chromium in Biological Samples by ICP-MS Using Hydrogen as a Reaction GasChromium is a key ingredient in a number of metal alloys used for metal implants which, despite being coated with inert surface layer coatings, can break down over time as a result of biocorrosion. Leeching of metal ions from implants into surrounding bone, tissue, and body fluids can cause severe health problems. Although the toxicity of the metal is low, there is a potential health risk if chromium ions enter the body. In ICP-MS, the chromium (52Cr) signal can be affected by interference from the recombination of background plasma 40Ar and sample-specific matrix 12C. To eliminate this interference, hydrogen can be used in the iCRC as a reaction gas to allow accurate analysis of 52Cr. Results using certified clinical standards of chromium in blood, plasma, urine, and serum clearly demonstrate the benefit of using hydrogen as a collision gas to remove the argon-carbide polyatomic interference. This study shows that ICP-MS is an essential tool for clinical monitoring of metal ions in complex matrices and that hydrogen iCRC gas allowed for greater accuracy and a lower level of quantitation in clinical matrices.
Latest:
A Convenient Alternative to MALDI and ESIAs was demonstrated by ESI and MALDI, and, more recently, ambient ionization approaches, successful new ionization methods can have an enormous impact on science. Novel ionization processes, such as inlet and vacuum ionization, are some of the latest of these approaches, and provide excellent alternatives to traditional approaches.
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Monitoring of Biological Matrices by GC–MS-MS for Chemical Warfare Nerve Agent DetectionA fluoride-regeneration approach enables biomonitoring of chemical warfare nerve agents.
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Simplifying Mass Spectrometry Through New Ionization Technology: Application to Drugs and Clinical AnalysesA newly discovered method is described for generating gas-phase ions from volatile and nonvolatile compounds. The method, matrix-assisted ionization (MAI), is both simple and sensitive, requiring only the vacuum inherent with all mass spectrometers and a suitable matrix, eliminating the need for lasers, electric fields, nebulizing gas, and even heaters to generate gas-phase ions. MAI is applicable for the direct analysis of drugs from biological fluids and tissue without prior purification. By placing matrix only on a specific surface area of interest and exposure to the vacuum of the mass spectrometer, ions are observed from compounds within the targeted surface area of tissue exposed to the matrix solution, thus allowing rapid and simple interrogation of “features of interest.” The limit of detection for drug standards is low attomoles and clean full mass range mass spectra are obtained from low femtomoles of the drug.
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The miniDOAS: Low Cost, High Performance Contactless Ammonia MeasurementsKnowledge of atmospheric ammonia concentrations is important, but ammonia is difficult to measure. We report here on the development of a low-cost ammonia measuring differential optical absorption spectroscopy (DOAS) instrument, based on a small sized and low priced spectrograph.
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Rapid Analysis of Selected Benzodiazepines by Automated SPE–MS-MSA new method was developed and validated using automated on-line solid-phase extraction (SPE) with tandem mass spectrometry (MS). Urine samples were enzyme-hydrolyzed and diluted before detection. The validated method was applied to positive authentic urine samples to evaluate concordance with high performance liquid chromatography (HPLC)–MS-MS results.
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Eliminating the Trade-Off Between Resolution and Throughput in Raman SpectroscopyAlthough Raman spectroscopy is an excellent analytical tool, Raman signals are often weak and traditional slit spectrometers typically have poor optical throughput, limiting their effectiveness in low light level setups.
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Tech Note — The Difference Between VFA and FT-IR SpectraThe basic characteristics of variable filter array (VFA) spectrometers, both near- and mid-infrared, make them well suited for routine infrared analysis applications outside and inside the laboratory. The performance of this spectrometer is discussed here.
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Raman Spectroscopy Applied to the Lithium-Ion Battery AnalysisThe application note explains how the Raman Spectroscopy can be helpful in the analysis of cathodes and anodes in Li-ion batteries.
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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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Molecular Characterization of Gadolinium-Doped Zinc Telluride Films by X-ray Photoelectron SpectroscopyZinc telluride films doped with gadolinium (ZnTe:Gd)-made by laser ablation and deposition-have been characterized by X-ray photoelectron spectroscopy (XPS) to determine the molecular species of the elements in the material and their presence as intentionally formed contaminants.
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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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A Sensitive and Cost-Effective LC–MS-MS Method for Determination of 1α,25-Dihydroxyvitamin D3 in Human PlasmaThe biologically active form of vitamin D is an important analytical target in both research and clinical practice.
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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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Pump Down and Vent Rate Tolerances of Moxtek WindowsMoxtek makes ultra-thin polymer X-ray windows that are often used in SEM and TEM microanalysis detectors.
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Handheld Laser-Induced Breakdown Spectrometer for In-field Elemental AnalysisSciAps has developed a handheld analyzer based on laser induced breakdown spectroscopy (LIBS).
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Raman Microscopy for Detecting Counterfeit Drugs — A Study of the Tablets Versus the PackagingResults of tablet matching measurements and characterization of packaging are presented.
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Measuring the Metal Content of Crude and Residual Fuel Oils by EDXRF: A Rapid, Alternative Approach to ICP-OESThis study explores the possibility of measuring the metal content of crude oils using EDXRF in samples as received in both the direct and indirect excitation mode.
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Identifying Textiles with Extended-Range NIR SpectroscopyFT-NIR spectroscopy is a useful tool to identify textile samples, with distinct spectral features observed at wavelengths >1350 nm. This approach can be applied to authentication of natural and synthetic consumer textile products.
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A Fast Method for Targeted Allergen Screening and Nontargeted Characterization for Personal Care ProductsCompounds that are added as fragrances to personal care products (PCPs) can also be allergens or skin irritants for some consumers. Knowing whether these compounds are present in a product is important for both consumers with known allergies and for manufacturers in order to be compliant with various regulations related to allergens. Here, a GC-TOFMS method was developed to screen for and quantify regulated allergens in approximately 5 minutes. This method utilized a short and narrow chromatographic column along with mathematical deconvolution of the TOFMS data to separate the target allergens from each other in the standards and from matrix interference in samples. Calibration equations were compiled for standards from 1 ppb to 1 ppm (on-column) with excellent linearity and correlation coefficients. These were applied to various commercially-available perfume and cologne samples to determine quantitative information for the targeted allergens. The full-mass range data acquisition also provided for non-targeted characterization and comparisons to better understand the aroma profile of each sample. The reported method reduced analysis time for allergen screening while simultaneously increasing the acquired information about the PCP samples.
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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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ADME/Tox Profiling Using Coulometric Electrochemistry and Electrospray Ionization Mass Spectrometry (PDF)The authors discuss the use of serial coulometric flow cells coupled online with electrospray ionization mass spectrometry in predictive assays for absorption, distribution, metabolism, excretion, toxicity (ADME/Tox), and stability implemented at early stages of drug discovery.
