Mass Spectrometry Reviews最新文献

Liquid chromatography-mass spectrometry (LC–MS) is a powerful technique for the detection and quantification of methylated quaternary ammonium compounds (mQACs), such as acylcarnitines and methylated amino-acid-derived (betainized) compounds, in biological matrices. Due to their high polarity and permanent charge, mQACs present analytical challenges, particularly in achieving efficient chromatographic retention and resolution. Here, we focus on the application of hydrophilic interaction liquid chromatography combined with mass spectrometric (HILIC–MS), for the analysis of these compound classes in biological samples. We highlight practical considerations in their analysis, including their MS/MS fragmentation patterns and identification in positive electrospray mode (ESI)⁺, to support researchers working with mQACs in targeted or untargeted metabolomics studies.

Lipopolysaccharides (LPS) are complex molecules embedded in the outer membrane of Gram-negative bacteria. LPS are highly heterogeneous across species and strains, posing a significant analytical challenge. This review article explores recent advances in the identification and characterization of LPS, with a particular focus on the role of mass spectrometry (MS) techniques. The review highlights how MS, in conjunction with various separation methods and spanning different ionization techniques and dissociation modes, has enabled more precise and sensitive determination of LPS composition, with a focus on lipid A structure. Finally, emerging trends in MS applications for LPS research are discussed and its potential to provide deeper insights into the development of antibiotic resistance among pathogenic bacteria.

Mass spectrometry-based proteomics is essential for advancing preventive and personalised medicine. Technological advancements have greatly increased both the number and sensitivity of spectra generated in a single experiment. Traditionally, spectra are identified using database search engines that depend on large and continuously expanding databases. This expansion enlarges the search space, posing challenges for controlling the false discovery rate in peptide identification. While many bioinformatic workflows employ rescoring algorithms as a post-processing step to manage false discoveries, preprocessing spectra offers a promising alternative. One such method, spectral quality assessment, classifies spectra as "high" quality (likely containing a peptide) or "low" quality (predominantly consisting of noise). This review provides a comprehensive perspective on spectral quality assessment, examining existing tools and their underlying principles. We discuss key considerations such as the definition of spectral quality, normalisation, the use of experimental training data, and future research in the field. By highlighting the potential of spectral quality assessment to improve peptide identification and reduce false discoveries, we aim to elaborate on its potential for the proteomics community.

Our healthcare system provides reactive sick-care, treating patients after symptoms have appeared by prescription of generic and often suboptimal therapy. This strategy brings along high costs and high pressure which is not sustainable. Alternatively, P5 healthcare is proposed focusing on five key elements: prevention, personalization, prediction, participation, psychocognition, however, changes in current clinical care pathways are required, for which antithrombin deficiency is a prime example. Hereditary antithrombin deficiency (ATD) is a genetic disorder, for which screening is instigated after a thrombotic episode. Current diagnostic tests for ATD lack sensitivity and refinement to correctly classify patients, and generic treatments are prescribed. A molecular understanding of ATD through a molecular diagnostic test that analyzes all clinically relevant features of antithrombin is required. Here, clinically relevant molecular characteristics of antithrombin, the diversity of antithrombin (deficiency) in heath and disease, and the strengths and weaknesses of antithrombin tests are reviewed. A mass spectrometry test that molecularly characterizes a patients antithrombin proteoforms harbors the highest potential to improve the clinical pathway for ATD. Application of this MS-based test in a future enhanced clinical pathway will improve patient management and outcome through molecular characterization of antithrombin and enables the promise of P5 healthcare for ATD.

Liquid chromatography-mass spectrometry (LC-MS) has become an indispensable tool for elucidating molecular structures and quantifying diverse compounds within complex mixtures. Despite its versatility, it faces various challenges such as ion suppression, low sensitivity, analyte instability, and matrix effects, which are being overcome by different kinds of offline and online derivatization techniques to improve specificity and reduce potential interferences. In this context, considerable advancements have been made in reviewing and critically evaluating a wide range of developed methods and techniques; however, little attention has been given to post-column derivatization (PCD) in LC-MS. Therefore, this comprehensive review highlights state-of-the-art advancements in LC-MS with a specific focus on various types of chemical and physical PCD, and in-source derivatization. It also examines the latest instrumentation developments, highlights methods and influencing factors, and explores applications in food, proteomics, biology, pharmaceuticals, and environmental analysis from the past four decades. Besides, this review critically examines the role of PCD in LC-MS along with outlining its advantages and disadvantages. Furthermore, special emphasis is also made on prospects and insights for developing more versatile LC-PCD-MS techniques and in-source methodologies, to address ongoing challenges and aim to open new research avenues for analysts.