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Introduction The matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) provides a fast, simple and cost-effective diagnosis in clinical microbiology laboratories, which is increasingly

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Authors: Károly Péter Sárvári, József Sóki, Miklós Iván, Cecilia Miszti, Krisztina Latkóczy, Szilvia Zsóka Melegh and Edit Urbán

(MALDI-TOF MS) provides accurate and fast identification results of Bacteroides species [ 3 ]. The aim of this study was to test the accuracy of MALDI-TOF MS identification system using 400 Hungarian Bacteroides clinical isolates and to retest the

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Lipids are important natural products and essential in nutrition, cosmetic formulations, pharmaceuticals, etc. Lipids and, particularly, phospholipids are of substantial medical interest (some are molecules with messenger function) and of diagnostic potential (for instance, the lipoproteins in human blood). Among the different soft-ionization mass spectrometric methods that enable detection of the intact lipid molecules, matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has several advantages, for instance, simple performance, high sensitivity, and robustness against contaminants. Additionally, MALDI-TOF MS analyzes a solid sample. This enables (in contrast with isotropic solutions) acquisition of spatially-resolved mass spectra (‘mass spectrometric imaging’). However, separation of complex mixtures into the individual lipid classes is normally required to enable detection of all the components. It will be shown with the example of a lipid extract from hens’ egg yolk that MALDI-TOF MS can be easily combined with TLC, enabling detection of as little as picomole amounts of lipids directly on the HPTLC plate. This results in sensitivities higher than those from established staining procedures. Additionally, because of the substantial spatial resolution, lipids separated by normal-phase TLC may not only be differentiated according to differences of their headgroups but also according to differences of their fatty acyl composition. Finally, MS-MS experiments, providing further insights into the structures of the relevant lipids, can be also performed directly on the HPTLC plate. Although the HPTLC-MALDI coupling can be easily established, there are different points to which special attention should be paid. Aspects of matrix application, data acquisition (including the stability of lipids and reproducibility), and data evaluation will be emphasized in this paper

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We report the case of a nosocomial infection due to Enterococcus cecorum isolated from a blood culture of a 75-year-old septic male patient. Matrix-assisted laser desorption–ionization time-of-flight mass spectrometry (MALDI-TOF MS) and Vitek 2 succeeded in identification of the isolate.

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Abstract  

Laser desorption ionization (LDI) mode of matrix-assisted laser desorptionionization time-of-flight mass spectrometry (MALDI-TOFMS) analysis of uranium(VI)leads to the formation of uranium oxides clusters, as with fast atom bombardment(FAB). Different uranium clusters than those with FAB were observed. Threedifferent families of formula (UO2)x Oy 2+, and two of formula (UO2)x Oy 2+ were found.

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appropriate study conditions (number 2) and followed the steps established to USP 38, the main guide for verification of microbial identification methods. Thus, the objective of this work was to evaluate the suitability of the MALDI-TOF MS technique for the

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Authors: A. Bischoff, M. Eibisch, B. Fuchs, R. Süss, M. Schürenberg, D. Suckau and J. Schiller

Summary

The analysis of lipid-phospholipid oxidation products is of primary importance. Although there are established HPLC and LC-MS techniques, it is shown here for the first time that the combination of matrix-assisted laser desorption and ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) and TLC represents a sensitive, fast, and convenient alternative. A mixture of 1-palmitoyl-2-linoleoyl-sn-phosphatidylcholine (PLPC) and -ethanolamine (PLPE) was oxidized under the influence of atmospheric oxygen and characterized by direct positive ion MALDI-TOF MS as well as combined TLC-MALDI. It is shown that much more detailed information — particularly related to the oxidation products of PLPE that have so far been scarcely investigated — can be obtained by TLC-MALDI. However, it is also shown that further methodological improvements are necessary to make this method generally applicable to complex lipid mixtures.

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Authors: Dagmara Stępień-Pyśniak, Agnieszka Marek, Tomasz Banach, Łukasz Adaszek, Ewelina Pyzik, Jarosław Wilczyński and Stanisław Winiarczyk

-ionization time-of-flight mass spectrometry (MALDI-TOF MS) system. Curr. Issues Pharm. Med. Sci. 27 , 137 – 141 . Kuhn , I. , Iversen , A. , Burman , L. G. , Olsson-Liljequist , B

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Authors: Erzsébet Nagy, Marianna Ábrók, Noémi Bartha, László Bereczki, Emese Juhász, Gábor Kardos, Katalin Kristóf, Cecilia Miszti and Edit Urbán

., et al.: MALDI-TOF MS in microbiological diagnostics-identification of microorganisms and beyond (mini review). Appl. Microbiol. Biotechnol., 2012, 93 (3), 965–974. Seng, P., Abat, C., Rolain, J. M., et al

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Authors: Béla Kádár, Béla Kocsis, Ákos Tóth, Katalin Kristóf, Péter Felső, Béla Kocsis, Katalin Böddi and Dóra Szabó

 µL of 0.1% trifluoroacetic acid (TFA) in water before the mass spectrometric measurement [ 20, 21 ]. Matrix-assisted laser desorption ionization time of flight/mass spectrometry (MALDI-TOF/MS) Mass analysis was

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