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Latest:
Monitoring Polymer Phase Transitions by Combining Rheology and Raman SpectroscopyThe in situ combination of rheometry and Raman spectroscopy allows for real-time, synchronized measurement of both physical and chemical material properties.
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IC–ICP–MS Speciation Analysis of As in Apple JuiceIn this study, apple juice samples are analyzed by IC–ICP–MS to determine the concentration of six arsenic species: the two inorganic, and highly toxic, species (As (V) and As [III]) and four organic species (arsenobetaine [AsB], arsenocholine [AsC], monomethylarsonic acid [MMA], and dimethylarsinic acid [DMA]).
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Enhancing the Sensitivity of Atmospheric Pressure Ionization Mass Spectrometry Using Flow Modulated Gas ChromatographyThe past decade has witnessed resurgent interest in coupling GC to atmospheric-pressure chemical ionization (APCI), which is suitable for the high column flows required for using flow modulation. This study assesses the use of GP-APCI with flow modulation for sensitive detection of selected trace organics.
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The Orbis Micro-XRF Analyzer SeriesBuilding on more than 10 years of Micro-XRF experience, the Orbis spectrometer yields a system with excellent Micro-XRF capability while setting a new standard in analytical flexibility. The Orbis incorporates a unique motorized turret integrating video and X-ray optics allowing coaxial sample view and X-ray analysis. The turret can accommodate two additional collimators along with the X-ray optic for a total of three X-ray beam sizes to expand the Orbis analytical capabilities beyond traditional Micro-XRF analysis.
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Metabolite Profiling Applications in Early Drug DiscoveryMetabolite profiling in drug discovery can contribute significantly at the lead optimization stage in two main application areas. The first is the identification of major metabolites, which provides medicinal chemists with information on the metabolic "soft spots." These soft spots are locations on the molecule particularly susceptible to metabolic modification, which can contribute to high pharmacokinetic clearance. This information then can be used to optimize the structure of a lead compound or chemical series to slow the rate of metabolism and therefore reduce hepatic clearance. This improves the absorption, distribution, metabolism, and excretion (ADME) properties of the compound, such as bioavailability, exposure (as measured by area under the curve), and half-life. Through iterative optimization of the structure and timely generation of metabolism data following each structural modification, pharmacokinetic properties can be improved while maintaining activity against the therapeutic target.
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Raman Analysis of Embedded ContaminantsRaman confocal spectroscopy is increasingly being applied for the analysis of embedded contaminants within materials. A non-contact, non-destructive analysis method, Raman spectroscopy requires very little sample preparation, has greater spatial resolution compared to FT-IR microscopy and the confocal analysis method allows visualization of materials within a clear sample matrix. This paper will investigate the analysis of an embedded contaminant within a polymer matrix on a glass substrate.
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Atomic Absorption: Feeding the Food Safety MarketWhile viewed as a mature technology, atomic absorption is still an attractive choice, particularly in the area of food safety.
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The Determination of Selenium in Shampoo by Flame Atomic Absorption SpectrometryThe formal European Union analytical method to measure and regulate the concentration of selenium disulphide is by the determination of selenium via flame atomic absorption spectrometry.
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Review of New Spectroscopic Instrumentation for 2018Our annual review of spectroscopy products, broken down into the following categories: Atomic Spectroscopy, Florescence, Mass Spectrometry, Mid-IR, NIR, NMR and ESR, Raman, UV-vis, X-ray, Software, Accessories, Components
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Online Identification of Flavones from Flos Chrysanthemi by LC–MS-IT-TOFThe use of medicinal herbs as alternative treatment methods continues to grow. With this escalating use has come an increasing interest in determining the chemical compositions of these herbs in order to obtain a better understanding of their makeup and effects. In this study, Flos Chrysanthemi, a commonly used traditional Chinese medicine that has been cultivated for centuries, was analyzed to identify the main flavone compositions in one original breed of Flos Chrysanthemi (Hangbaiju) in China.
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Meeting the Surge in Demand for Seafood Screening on the Gulf CoastThe authors look at the use of QuEChERS in the ongoing testing program in the gulf.
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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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Using LC–oa-TOF MSE with a Multivariate Statistical Sample Statistical Sample Profiling Strategy to Distinguish Chinese Red Ginseng from Korean Red GinsengBoth Chinese ginseng and Korean ginseng are similar plant species and undergo similar handling procedures when harvested and processed for sale. Despite their similarities, Korean ginseng commands a higher price than Chinese ginseng on the open market and is believed to produce different clinical effects than Chinese ginseng. Chinese researchers are now employing new techniques on the two varieties of ginseng to understand their chemical differences. HPLC/UV-based strategies for distinguishing the two types of ginseng have proven to be mostly ineffective due to lack of resolution. Using UltraPerformance liquid chromatography/orthogonal acceleration (oa)–TOF mass spectrometry and exact mass measurement, the authors developed a high-resolution method using multivariate statistical analysis for separating and identifying differences between Chinese ginseng and Korean ginseng at the molecular level.
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Ultratrace Aluminum Analysis of Nutritional Intravenous Solution Components in 1-Propanol Using GFAAS (PDF)This article describes how ultratrace aluminum analysis of two nutritional intravenous solution components with limited water solubility can be performed by graphite furnace atomic absorption spectroscopy (GFAAS) with dissolution in 1-propanol.
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Why and How to Avoid Ionic Contamination in Water Used for LC–MS AnalysesIonic contaminants in the water used in UHPLC analyses with MS detection method lead to adduct formation and reduced analytical signals because of ion suppression. In MS, the preferred ion type is the protonated molecular ion, especially in peptide analysis, since the partially mobile proton charge enables more meaningful fragmentation analysis, as compared to a sodiated peptide ion.
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Spectroscopic Monitoring of the Enrichment of Chlorin e6 in Tumors of the SkinFor the optimization of photodynamic therapy the spectroscopic detection of photosensitizer molecules, which are selectively enriched in tumour cells, can be useful.
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Using LC–oa-TOF MSE with a Multivariate Statistical Sample Statistical Sample Profiling Strategy to Distinguish Chinese Red Ginseng from Korean Red GinsengBoth Chinese ginseng and Korean ginseng are similar plant species and undergo similar handling procedures when harvested and processed for sale. Despite their similarities, Korean ginseng commands a higher price than Chinese ginseng on the open market and is believed to produce different clinical effects than Chinese ginseng. Chinese researchers are now employing new techniques on the two varieties of ginseng to understand their chemical differences. HPLC/UV-based strategies for distinguishing the two types of ginseng have proven to be mostly ineffective due to lack of resolution. Using UltraPerformance liquid chromatography/orthogonal acceleration (oa)–TOF mass spectrometry and exact mass measurement, the authors developed a high-resolution method using multivariate statistical analysis for separating and identifying differences between Chinese ginseng and Korean ginseng at the molecular level.
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Raman Spectroscopy of DocumentsDocuments have been investigated to determine the feasibility of utilizing Raman and SERS Raman spectroscopy for the identification and characterization of inks on paper. Fluorescence reduction methods have been employed to facilitate the analysis by reducing the nascent fluorescence from paper and ink. Furthermore, ink crossings were investigated to demonstrate that ink applied after creation of a document could be differentiated from the originally applied ink.
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Meeting the Surge in Demand for Seafood Screening on the Gulf CoastThe authors look at the use of QuEChERS in the ongoing testing program in the gulf.
Latest:
The Applicability of Field-Portable GC–MS for the Rapid Sampling and Measurement of High-Boiling-Point Semivolatile Organic Compounds in Environmental SamplesIn this study we report on the use of a field-portable GC-MS with rapid sampling techniques such as solid-phase micro extraction, purge-and-trap, thermal desorption, and heated headspace to provide a fast response for in-field-SVOCs analyses for a wide variety of environmental-type samples including potable waters, tea, plants and road gravel. We will show that this field-portable approach can provide the required sensitivity, selectivity for the effective analysis of SVOCs with very high boiling points such as polycyclic aromatic hydrocarbon (PAHs), pesticides, phenolic compounds and phthalate esters in a number of different field-based samples, in less than 10 minutes.
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The Exception to the Conference Industry's RuleFor anyone who makes his or her living in the field of analytical chemistry, and more specifically, in the fields of chromatography or spectroscopy, the debate concerning the state of the conference industry is well known to say the least.
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Mars Express Finds Evidence of Liquid Water on MarsSince the discovery of gullies on Mars in 2000, NASA has endeavored to re-image areas known to have them. Now for the first time, using before and after images taken of the same region on Mars, a dune gully flow is shown to have happened very recently.
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Single Multipoint Calibration Curve for Discovery BioanalysisA single calibration curve run with staggered calibrants bracketing the unknowns is compared to running complete duplicate calibration curves, one at the beginning and one at the end of unknown sample analysis in an effort to accelerate discovery bioanalysis.
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High-Throughput Trace Analysis Using SERS-Coated Microtiter Plates with a Raman Plate ReaderSurface-enhanced Raman spectroscopy (SERS) has been studied extensively over the last few decades with many advances in preparation of SERS substrates and coatings. While the bulk of the research in SERS substrate preparation has been devoted to pushing detection limits to higher sensitivity for measurement of single samples, the application of SERS to high-throughput analysis has been largely ignored. In this article, we present the use of commercially available SERS-coated microtiter plates in a dedicated Raman microtiter plate reader, enabling high-throughput trace analysis measurements. This article also describes the SERS substrate, the high-throughput plate reader, and preliminary results from samples representing trace analysis of explosives, nerve agents, pharmaceuticals, and biological compounds.
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ADME/Pharmacokinetic Studies from Serum and Plasma: Improvements in Sample Preparation and LC–MS Analysis of Therapeutic OligonucleotidesThe authors discuss improvements in sample preparation for ADME/pharmacokinetic studies of therapeutic oligonucleotides.
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Phosphorylation Site Localization Using Probability-Based ScoringThe development of a phosphorylation probability scoring tool in an automated data search engine resolves ambiguity in site localization when compared to manual methods.
Latest:
Using LC–oa-TOF MSE with a Multivariate Statistical Sample Statistical Sample Profiling Strategy to Distinguish Chinese Red Ginseng from Korean Red GinsengBoth Chinese ginseng and Korean ginseng are similar plant species and undergo similar handling procedures when harvested and processed for sale. Despite their similarities, Korean ginseng commands a higher price than Chinese ginseng on the open market and is believed to produce different clinical effects than Chinese ginseng. Chinese researchers are now employing new techniques on the two varieties of ginseng to understand their chemical differences. HPLC/UV-based strategies for distinguishing the two types of ginseng have proven to be mostly ineffective due to lack of resolution. Using UltraPerformance liquid chromatography/orthogonal acceleration (oa)–TOF mass spectrometry and exact mass measurement, the authors developed a high-resolution method using multivariate statistical analysis for separating and identifying differences between Chinese ginseng and Korean ginseng at the molecular level.
Latest:
Using LC–oa-TOF MSE with a Multivariate Statistical Sample Statistical Sample Profiling Strategy to Distinguish Chinese Red Ginseng from Korean Red GinsengBoth Chinese ginseng and Korean ginseng are similar plant species and undergo similar handling procedures when harvested and processed for sale. Despite their similarities, Korean ginseng commands a higher price than Chinese ginseng on the open market and is believed to produce different clinical effects than Chinese ginseng. Chinese researchers are now employing new techniques on the two varieties of ginseng to understand their chemical differences. HPLC/UV-based strategies for distinguishing the two types of ginseng have proven to be mostly ineffective due to lack of resolution. Using UltraPerformance liquid chromatography/orthogonal acceleration (oa)–TOF mass spectrometry and exact mass measurement, the authors developed a high-resolution method using multivariate statistical analysis for separating and identifying differences between Chinese ginseng and Korean ginseng at the molecular level.
Latest:
Quantitative Proteomic Workflow for Discovery of Early Rejection Kidney Transplant Peptide Biomarkers and Subsequent Development of SRM Assays in UrineThe authors discuss a noninvasive method for determining early indications of the rejection of a kidney transplant.
