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It makes intuitive sense - the higher the sensitivity of an inductively coupled plasma–mass spectrometry (ICP-MS) system, the lower the detection limit. But there are many factors that affect the detection limit for a given isotope in a given sample. These factors include sensitivity, background noise, and interferences.

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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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Spectroscopy's annual overview of new instrumentation presented at the PittCon conference.

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For analysis of non-particulate solids, the diffuse reflection sampling technique may offer an easy, non-destructive method for mid-infrared measurements. Spectral results of a polypropylene face mask collected via diffuse reflection and attenuated total reflection (ATR) were compared.

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Thermo Fisher Scientific

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The polymer processing can impact FTIR-ATR spectra, and if these processing factors are not considered may lead to incomplete or inconsistent results.

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Thermo Fisher Scientific

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This article describes a fully automated online solid-phase extraction–liquid chromatography–tandem mass spectrometry (SPE–LC–MS-MS) setup using a mass spectrometer and an electrospray ionization probe for analyzing different groups of polar contaminants in natural waters. The goal was to develop an online SPE method for the quantification of sulfonamide antibiotics, including their acetyl metabolites, as well as for frequently used pesticides (triketones, phenylureas, chloracetanilides, phenoxyacetic acids, amides, and triazines) in ambient waters. The analytical methods were applied successfully for a field study in an agricultural region within the catchment area of Lake Greifensee near Zurich, Switzerland.

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Recent federal science and technology initiatives are focusing public attention and funding on the need for innovative research in environmental quality, sustainability, medicine, and advanced materials.

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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 column is the continuation of our previous column that describes and explains some algorithms and data transforms beyond those most commonly used. We present and discuss algorithms that are rarely, if ever, seen or used in practice, despite that they have been proposed and described in the literature.

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Lambda Solutions, Inc.