Mass Spectrometry

Nowadays, biotherapeutic proteins are available in different formats such as fusion proteins, monoclonal antibodies, or antibody-drug conjugates. The complexity of these molecules requires advanced and comprehensive characterization to guarantee their potency and safety. This work provides an overview of a methodology using an innovative capillary electrophoresis-tandem mass spectrometry coupling (CE-MS-MS) for the characterization of biologics primary structure. This method was applied to perform biosimilarity assessment between two mAbs, distinguishing minor differences like a sole amino acid substitution. Such a level of characterization is permitted by cumulating the specificities of both CE and high-resolution tandem MS using a sheathless interface, therefore renewing the interest for this type of coupling.

The quality and safety of ready-to-eat packaged foods-such as salads-is very difficult for consumers and suppliers to judge, and improving this situation is the focus of a Europe-wide research project. Part of the project is devoted to the development of better methods to detect and analyze the volatile organic compounds released from relevant food types, in an effort to identify biomarkers for quality and microbial contamination. This article examines one important food (melon) and shows how a method based on thermal desorption (TD) with gas chromatography-time-of-flight-mass spectrometry (GC–TOF-MS) can elucidate how key volatiles vary with time of storage and with the size of the melon pieces. The article highlights how such analytical information will be of value in efforts to improve the quality and safety of ready-to-eat foods.

There is often insufficient prevention to ensure safe swimming environments. Recreation water illness (RWI), most commonly in the form of digestional track illness as well as skin, ear, and respiratory infections, are often caused by water contamination from human waste. Stercobilin is a very stable and suitable chemical biomarker of human waste that has the potential to be used for waste monitoring in public swimming facilities. Using solid phase extraction (SPE) techniques paired with high-resolution mass spectrometry (HRMS), we have developed a robust method used for swimming pool water monitoring to create safer swimming environments.

Do the signal-to-noise ratios presented by instrument vendors accurately reflect improvements in mass spectrometers? We review factors influencing the validity of vendor SNR specifications, and argue that the statistical alternative of instrument detection limits is more consistent with regulatory guidelines and a more relevant indicator of instrument performance.

Beyond the long-established, optical standard techniques of photometry and immunoassay, LC-API-MS-MS has opened new horizons for clinical pathology. This is related to biomedical research and standardization as well as to routine diagnostic testing. It can be expected that the latter field will see important growth, including the introduction of automated MS-based analyzer systems. This will shift the application of mass spectrometric tests from a few specialized laboratories to many standard clinical laboratories with a lower level of analytical expertise.

We recently spoke to Gary Duncan and Wendy Russell of the Rowett Institute of Nutrition & Health in Aberdeen, Scotland, about the significance of phytochemical bioavailability to human health and the important role of liquid chromatography linked to tandem mass spectrometry (LC–MS-MS) in their research.

Worldwide trends in illicit drug use and production have shifted toward an increase in synthetic analogues and the emergence of new variations in their manufacture.

In most countries, herbal medicinal products (HMPs) are introduced into the market without proper scientific evaluation or enforced safety and toxicological studies.

This article describes the development of a new data-independent acquisition (DIA) workflow for protein quantification that uses a mass spectrometer that combines three types of mass analyzers to achieve lower limits of detection (LOD), higher sensitivity, more accurate quantitative results, wider dynamic range, and better reproducibility than existing high-resolution accurate-mass (HRAM) tandem mass spectrometry (MS-MS) DIA workflows.

A multiresidue method has been developed and validated for the analysis of methylxanthines (caffeine and its metabolites) and cotinine in human plasma.

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This interview with Steven J. Ray, an Associate Scientist in the Department of Chemistry at Indiana University in Bloomington, Indiana, discusses his work with a new form of mass spectrometry (MS) for analyzing complex samples.

Military jet fuel (JP-8) is very similar to commercial jet fuel (Jet A) except for the presence of three additives, fuel system icing inhibitor, corrosion inhibitor–lubricity improver (CI-LI), and antistatic additive, which are added to improve characteristics of JP-8.

Direct sample analysis coupled to high-resolution time-of-flight mass spectrometry (TOF-MS) may be effective at analyzing synthetic cathinones, especially for qualitative analysis, because it does not require potentially tedious sample preparation.

Canola largely contains unsaturated fatty acids, thus rendering it clear in most cases after extraction and refining.

Simple, sensitive, rapid, selective, and precise reversed-phase liquid chromatography (LC), electrospray ionization mass spectrometry (ESI-MS), and tandem MS (ESI-MS-MS) methods were developed and validated for the determination of 2-hydroxy-4-(methylthio)-butanoic acid (HMTBA) in bovine serum and sea water matrix. HMTBA is the ?-hydroxy analog of the sulfur-containing amino acid methionine and is extensively used as a methionine supplement in poultry and bovine feed.

Native mass spectrometry, the method by which noncovalent protein complexes are retained in the gas phase for intact mass analysis, is gaining interest as a method for intact protein characterization. The development of a modified orbital ion trap platform for high-resolution analyses has expanded the role of native mass spectrometry to address the challenges of intact protein characterization.

Ionization of small, large, volatile, and nonvolatile compounds with charge states nearly identical to electrospray ionization are produced from a solid matrix or solution with high sensitivity utilizing the vacuum inherent with any mass spectrometer. With the proper matrix, analytes can be analyzed from ambient conditions or by direct introduction into vacuum.

The identification of nontargeted species in environmental and commercial samples by mass spectrometry can be very difficult. In this article, authors from Eastman Chemical Company describe their systematic approach for the identification of nontargeted species using nominal and accurate mass data, searching both mass spectral and "spectra-less" databases.

In this article, we examine how tandem and tandem hybrid mass spectrometry has opened up new frontiers already. We go further and examine how lesser-known experiments are breaking new ground, with alternative fragmentation techniques, as well as the addition of extra levels of orthogonality by parallel separations techniques.

Mass spectrometry is a powerful analytical tool. Yet researchers and instrument makers continue to push the limits of its resolving power. One such researcher is David E. Clemmer, the Robert & Marjorie Mann Chair and Distinguished Professor of Chemistry at Indiana University in Bloomington, Indiana and the 2014 Anachem Award winner. Clemmer's group has done extensive research to develop and improve ion trapping techniques and ion mobility spectrometry-mass spectrometry (IMS-MS) instruments to analyze biomolecular mixtures and structures.

The production and sale of counterfeit drugs has risen sharply in recent years. The World Health Organization (WHO) estimates that counterfeit medicines account for approximately 1% of sales in developed countries and well over 10% in developing countries.

Here, a method to characterize edible oils and edible oil mixtures through fingerprinting and the isolation of individual analyte differences is reported. Aroma and flavor analytes in extra virgin olive, olive, peanut, grapeseed, and vegetable oils were sampled with headspace solid-phase microextraction (HS-SPME).

Despite the advantages of soft ionization ion-source technologies for improving confidence in the identification of a range of challenging analytes, soft ionization remains a niche technique for gas chromatography–mass spectrometry (GC–MS).

Translational proteomics has not been as successful as originally anticipated. Because mass spectrometry (MS) can separate proteins at the sequence level, it provides the selectivity needed for this application; however, traditional challenges still exist, including time-to-result, throughput, and sample-size requirements.