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Charakterystyka wybranych metod izolacji i identyfikacji drobnoustrojow w żywności

Hać-Szymańczuk Elżbieta

Przemysł Spożywczy

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2023

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T. 77, nr 11

24--28

PL

Szybkie wykrycie i identyfikacja drobnoustrojów występujących w żywności jest głównym celem dla laboratoriów mikrobiologicznych. W ostatnich latach klasyczne metody analizy mikrobiologicznej są uzupełniane o nowoczesne metody analityczne i molekularne. W niniejszym artykule omówiono następujące metody: fluorescencyjną hybrydyzację in situ (FISH), metody PCR i RT-PCR, spektrometrię masową MALDI-TOF i cytometrię przepływową. Opisano również zasadę działania i dobór podłoży chromogennych służących do wykrywania i identyfikacji drobnoustrojów w produktach spożywczych.

EN

The rapid detection and identification of microorganisms found in food is the main goal for microbiology laboratories. In recent years, classical methods of microbiological analysis have been supplemented with modern analytical and molecular methods. This article discusses the following methods: fluorescence in situ hybridization (FISH), PCR and RT-PCR methods, MALDI-TOF mass spectrometry and flow cytometry. The principle of operation and the selection of chromogenic media for their detection and identification of microorganisms in food products are also described.

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Prekatalizatory oligomeryzacji olefin oparte na kationach chromu(III) oraz kobaltu(II) : właściwości fizykochemiczne oraz katalityczne

Malinowski Jacek, Drzeżdżon Joanna, Sikorski Artur, Jacewicz Dagmara Elżbieta

Wiadomości Chemiczne

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2022

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[Z] 76, 11-12

943--962

EN

The introduction describes the most important facts about the development of polyolefins. This is followed by a description of the role of polyolefins and the most important applications in industry and everyday life. The paper presents new, highly active precatalysts for oligomerization of olefins. These are coordination compounds based on chromium(III) cation, anions of various polycarboxylic acids and auxiliary ligands, such as 1,10-phenanthroline or 2,2'-bipyridyl. This review presents their crystallographic structures and basic parameters describing the elementary cell. The catalytic properties of the obtained oligomerization products using chromium(III) coordination compounds by MALDI-TOF MS are described. In conclusion, the presented precatalysts are compared with others described in the literature.

3

Maldi – metoda do zastosowań w analizie strukturalnej polimerów

Swinarew B., Swinarew A. S.

Wiadomości Chemiczne

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2014

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[Z] 68, 7-8

645--660

EN

Polymers as one of the fastest growing groups of widespread use of synthetic materials are characterized by a great diversity of structures. Structural characterization of polymers generally includes: an assessment of the average molecular weight (Mn) and the molar mass distribution (PD) to determine the structure of repeating units (mers) sequence analysis of the copolymer, identification of the end groups, the detection and identification of contaminants and substances present in the composition of the polymer asa dopant. Modern mass spectrometry (MS) offers the opportunity to study the smallest structural details of macromolecular materials [1–10]. Because of the variety of potential structures of polymer analysis process is to answer a few questions by a certain pattern. The first step is to determine the chemical structure of the polymer backbone. The second step is to identify whether the chains have branching points and define the degree of branching. The third important step is to correct end groups identification, also for the detection of cyclic oligomers that can be present. The structural studies can be made by mass spectrometer using reflectron mode. In the essence, the method involves three steps. The first analysis is performed with standard mass spectrum of the sample. Then the precursor ion (parent ion) is selected, which is subjected to further analysis by MS changed voltages and reflectron mode. This paper aims to present the issues related to the detailed analysis and characterization of polymeric materials produced on a large scale. Before, for materials such as poly(propylene), poly(ethylene), poly(styrene), polycarbonate, etc., increasing demands on the mechanical and technological parameters were placed. Maintaining a high level of products is associated with a very rigorous process control of the manufacturing, processing and transportation at every stage. The optimal tool for the structural characteristics of these polymeric materials is the defense technique MALDI-TOF MS (Matrix-Assisted Laser Desorption/Ionization Time- -Of-Flight Mass Spectrometer) due to its versatility, speed and extremely high precision. Below, we present some aspects of MALDI MS analysis of polymeric materials and composites. Note, that the following literature review focuses on the recent developments in the field of preparation of the samples, to achieve high mass resolution, the identification of polymers and copolymers, the accuracy of the molar mass determination and the identification of functional end groups, sequence analysis of the copolymer.

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Mass spectrometry based analysis of erythrocyte membrane associated proteins in chronic myeloid leukemia patients in Sri Lanka

Kottahachchi D. U., Ariyaratne T. R., Jayasekera G. A. U.

International Letters of Chemistry, Physics and Astronomy

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2014

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Vol. 19, iss. 1

74--86

EN

The research reported in this paper was conducted to analyze erythrocyte membrane associated proteins (ERMBPs) of some of chronic myeloid leukemia (CML) patients and selected individuals of Sri Lanka employing one dimensional sodium dodecyl sulphate poly acrylamide gel electrophoresis (1D-SDS-PAGE) combined with matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI–TOF-MS). Erythrocyte membranes from blood were isolated by osmotic lysis, centrifugation and washings. ERMBPs were separated on 1D-SDS-PAGE, visualized by silver staining and the separated protein bands dissected out from the gel and were subjected to digestion by proteolytic enzyme, trypsin, and the resulting peptide mixture was analyzed by MALDI-TOF-MS. Resulting experimental peptide mass values were analyzed by peptide mass fingerprint (PMF) technique. From this analysis 10 ERMBPs including α and β spectrin, ankyrin, band 3, band 4.1, band 4.2, band 7, dematin, actin, 55 KDa erythrocyte membrane protein were identified accurately with their primary structure information. The study was able to provide some evidence for Cathepsin associated cleavage of Band 3 anion transport protein in CML patients reported previously. In addition we were able to detect changes in gel bands between healthy controls and CML patients around the area of 20 kDa in the 1 D-SDS-PAGE. It was identified as nuclear protein Dbf 4 related factor 1 isoform 2. Although erythrocytes are devoid of nuclei, such unexpected nuclear proteins have been identified in previous research. We were successful in identifying several human ERMBPs with available resources. As the identified proteins were known to be related to pathology of some of the hematological diseases, this methodology could be extended to detect the protein changes in erythrocyte membrane protein associated diseases. Therefore, this initial research would at some point lead to discovery of biomarkers to these hematological diseases in Sri Lanka.

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A simple TLC-MALDI method to monitor oxidation products of phosphatidylcholines and -ethanolamines

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

Acta Chromatographica

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2011

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Vol. 23, no. 2

365--375

EN

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.