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A new time-of-flight mass spectrometer was evaluated for performing simultaneous metabolic stability measurement and metabolite identification with ultrahigh-pressure liquid chromatography. Six representative compounds (clomipramine, diclofenac, imipramine, haloperidol, verapamil, and midazolam) were incubated in rat liver microsomes at a more physiologically relevant substrate concentration (1 ?M). High-resolution full-scan and product-ion spectra were acquired in a single injection using generic methodology. Quantitative clearance of the parent was measured using the full-scan data. Major metabolites were identified using the accurate mass product ion spectra. High scanning speed allowed for a sufficient number of data points to be collected across the chromatographic peak for quantitative analysis. Sensitivity was sufficient for obtaining meaningful kinetics with a 1 ?M initial substrate concentration.

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Assay sensitivity is the lowest concentration at which a targeted analyte can be measured and is often limited by chemical background or co-eluting interferences. FAIMS in combination with liquid chromatography (LC) and zero neutral loss tandem MS was used to remove chemical background and co-eluting interferences from the analysis of linoleic acid in cancer cell extracts. Concentration of endogenous linoleic acid was determined from back-calculation of standard calibration samples fortified with deuterium-labeled linoleic acid. No internal standard was used. LC–MS-MS analysis of the cancer cell extracts resulted in an increase in signal-to-noise ratio of 10-fold. The assay sensitivity was increased 10 times over the traditional LC–MS-MS experiment exclusively due to the new FAIMS technology.

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Thermo Fisher Scientific

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State-of-the-art mass spectrometry (MS) techniques of growing importance to life sciences research now include not just liquid chromatography (LC)–MSn (n = 2–11), but also LC–matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF), LC-MALDI-TOF-TOF, electrospray ionization (ESI)-TOF, and LC-Fourier transform (FT) MS.

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State-of-the-art mass spectrometry (MS) techniques of growing importance to life sciences research now include not just liquid chromatography (LC)–MSn (n = 2–11), but also LC–matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF), LC-MALDI-TOF-TOF, electrospray ionization (ESI)-TOF, and LC-Fourier transform (FT) MS.

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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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Thermal decomposition provides valuable information about the chemical composition of a material. Although thermal gravimetric analysis (TGA) measures small weight losses during a heating ramp, it cannot identify the chemicals corresponding to the weight loss.

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Reproducing analysis conditions is crucial to achieving consistent, accurate results in gas chromatography–mass spectrometry (GC–MS). Valid reproduction demands appropriate application of technique, solid method design, reliable and accurate equipment, and a dedicated team of well-practiced technicians and researchers. But even when all these conditions are met, users can be held back by the more subtle elements in GC–MS operations, such as cutting or changing a column, or setting up the same experiment on different equipment. Even getting the parameters of a test organized so that it can be reproduced elsewhere - in a laboratory across the hall, the country, or the world - can be daunting. Consistent GC–MS results depend upon retention-time reproducibility.

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Root diseases caused by soilborne plant pathogens are responsible for billions of dollars of losses annually in food, fiber, ornamental, and biofuel crops. The use of pesticides often is not an option to control plant diseases because of economic factors or potential adverse effects on the environment or human health. For this reason, many Americans are now buying pesticide-free organic foods. Organic agriculture has few options for controlling pests and thus must make full use of natural microbial biological control agents in soils that suppress diseases.

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Drug discovery scientists are continually striving to improve productivity and efficiency in their workflows. From early discovery to clinical development, existing workflow bottlenecks represent an opportunity to develop solutions to speed the process and improve productivity. The key requirements for quantitative analysis are precision, accuracy, and linear dynamic range. With any quantitative instrument, the hope is that it will be applicable to a vast range of coumpounds, ruggest, and fast. New mass spectrometry (MS) technologies are being developed that meet these criteria and permit high throughput while enabling its application to areas in which speed limitations previously curtailed its practicality. In particular, in the area of ADME profiling, new MS platforms are becoming available that increase the throughput by at least 25-fold, by combining the speed of matrix-assisted laser desorption ionization (MALDI) with the specificity of triple-quadrupole MS. This is bound to greatly accelerate the ADME..

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State-of-the-art mass spectrometry (MS) techniques of growing importance to life sciences research now include not just liquid chromatography (LC)–MSn (n = 2–11), but also LC–matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF), LC-MALDI-TOF-TOF, electrospray ionization (ESI)-TOF, and LC-Fourier transform (FT) MS.

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Drug discovery scientists are continually striving to improve productivity and efficiency in their workflows. From early discovery to clinical development, existing workflow bottlenecks represent an opportunity to develop solutions to speed the process and improve productivity. The key requirements for quantitative analysis are precision, accuracy, and linear dynamic range. With any quantitative instrument, the hope is that it will be applicable to a vast range of coumpounds, ruggest, and fast. New mass spectrometry (MS) technologies are being developed that meet these criteria and permit high throughput while enabling its application to areas in which speed limitations previously curtailed its practicality. In particular, in the area of ADME profiling, new MS platforms are becoming available that increase the throughput by at least 25-fold, by combining the speed of matrix-assisted laser desorption ionization (MALDI) with the specificity of triple-quadrupole MS. This is bound to greatly accelerate the ADME..

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Thin-layer chromatography (TLC) is a widely used technique for the rapid examination of compound purity. The amount of qualitative information, however, is limited to the retention factor of compounds. The technique described here enables the direct determination of TLC plates by MALDI MS.

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Mass spectrometry (MS) has advanced to analyze ever-larger biomolecules with the invention of soft ionization techniques like electrospray ionization (ESI). Although ESI has provided a method of generating ions of high mass, mass spectrometers generally suffer both lower sensitivity and lower resolution as the mass-to-charge ratio of an ion increases. To extend the mass range of ionized macromolecules beyond the limits of MS, macroion mobility spectrometry utilizes ion mobility sizing to characterize charge-reduced ESI-generated macroions from >5 kDa to beyond megadalton masses. One prominent application of macroion mobility spectrometry, highlighted here, is the high sensitivity analysis of intact proteins, antibodies, and conjugates in which molecular masses range from antibody light-chain fragments to high mass immunoglobulin multimers.

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Assay sensitivity is the lowest concentration at which a targeted analyte can be measured and is often limited by chemical background or co-eluting interferences. FAIMS in combination with liquid chromatography (LC) and zero neutral loss tandem MS was used to remove chemical background and co-eluting interferences from the analysis of linoleic acid in cancer cell extracts. Concentration of endogenous linoleic acid was determined from back-calculation of standard calibration samples fortified with deuterium-labeled linoleic acid. No internal standard was used. LC–MS-MS analysis of the cancer cell extracts resulted in an increase in signal-to-noise ratio of 10-fold. The assay sensitivity was increased 10 times over the traditional LC–MS-MS experiment exclusively due to the new FAIMS technology.

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More than 20 years passed after the introduction of Fourier transform–ion cyclotron resonance mass spectrometry (FT-MS) before advancements in electronics and computer technology enabled the development of practical, high-performance instruments. Modern analytical FT-MS instruments rely on sophisticated electronic circuitry and powerful computer software to achieve the dramatic resolving power and mass accuracy typical for the instrumentation. Here, the power of modern hybrid FT-MS instrumentation is discussed by demonstrating the capability of this instrumentation for selected applications such as the analysis of crude oil, intact protein, and fragile noncovalent complex samples.

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Mass spectrometers are effective for identifying and quantifying unknown molecules, such as disease-related proteins and small molecules in pharmaceutical research and medical diagnosis. In addition, mass spectrometry (MS) can be particularly powerful when analyzing molecules with complex structures, such as posttranslationally modified proteins. Among various MS approaches, high-resolution multistep tandem MS (MS-MS) is an emerging methodology for accurate identification of complex molecules. In this article, we describe a new approach for mass analysis with enhanced quantitative capability combined with high-resolution multistep MS-MS, where the dynamic range of quantitation covers four orders of magnitude.

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This “Chemometrics in Spectroscopy” column traces the historical and technical development of these methods, emphasizing their application in calibrating spectrophotometers for predicting measured sample chemical or physical properties—particularly in near-infrared (NIR), infrared (IR), Raman, and atomic spectroscopy—and explores how AI and deep learning are reshaping the spectroscopic landscape.

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Lambda Solutions, Inc.

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Mass spectrometry (MS) has advanced to analyze ever-larger biomolecules with the invention of soft ionization techniques like electrospray ionization (ESI). Although ESI has provided a method of generating ions of high mass, mass spectrometers generally suffer both lower sensitivity and lower resolution as the mass-to-charge ratio of an ion increases. To extend the mass range of ionized macromolecules beyond the limits of MS, macroion mobility spectrometry utilizes ion mobility sizing to characterize charge-reduced ESI-generated macroions from >5 kDa to beyond megadalton masses. One prominent application of macroion mobility spectrometry, highlighted here, is the high sensitivity analysis of intact proteins, antibodies, and conjugates in which molecular masses range from antibody light-chain fragments to high mass immunoglobulin multimers.

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In 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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Here we describe a new compact device for electron-capture dissociation (ECD) analysis of large peptides and posttranslational modifications of proteins, which can be difficult to analyze via conventional dissociation techniques such as collision-induced dissociation (CID). The new compact device realizes ECD in a radio frequency (RF) linear ion trap equipped with a small permanent magnet, which is significantly different than the large and maintenance-intensive superconducting magnet required for conventional ECD in Fourier-transform ion cyclotron resonance mass spectrometers. In addition to its compactness and ease of operation, an additional merit of an RF linear ion trap ECD is that its reaction speed is fast, comparable to CID, enabling data acquisition on the liquid-chromatography (LC) time scale. We interfaced the linear-trap ECD device to a time-of-flight mass spectrometer to obtain ECD spectra of phosphorylated peptides injected into a liquid chromatograph, infused glycopeptides, and intact small..

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A much discussed issue related to near infrared analysis (NIR) is the necessity of sample preparation. Ground and unground samples of wheat were analyzed to determine how truly necessary it is to homogenize samples before NIR analysis. The new Retsch TWISTER mill, specifically designed for NIR sample preparation, was utilized for this comparative study.

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Thin-layer chromatography (TLC) is a widely used technique for the rapid examination of compound purity. The amount of qualitative information, however, is limited to the retention factor of compounds. The technique described here enables the direct determination of TLC plates by MALDI MS.

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The authors discuss the use of electron-capture dissociation coupled with a linear ion trap time-of-flight mass spectrometer to investigate the structure of human transferrin.

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Multiline analysis, which consists of using several lines per element to detect positive or negative bias caused by spectral interferences, is an ideal way to use all the information emitted by the plasma and collected by a charge-coupled device detector. However, method development and validation become more complex. Dedicated software has been developed to overcome it, and analysis of geological samples will illustrate their benefit in achieving high reliability of results.

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This article describes the use of an in-line, autodilution, and autocalibration sample delivery system coupled to an inductively coupled plasma–mass spectrometry system to analyze a group of over-the-counter pharmaceutical products.

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To optimize the mapping collection parameters, it is important to factor the size of the mapping area, the beam diameter, and the desired beam spacing. For this sample, the area being mapped is shown in red outline in Figure 2, approximately 50.4 x 3.5 mm.