scholarly journals Mass Spectrometry Coupled with Chromatography toward Separation and Identification of Organic Mixtures

2021 ◽  
Author(s):  
Asmae Bouziani ◽  
Mohamed Yahya
Keyword(s):  
Mass Spectrometry ◽  
Liquid Phase ◽  
Chemical Structure ◽  
Molecular Composition ◽  
The Other ◽  
Complex Mixtures ◽  
Compound Identification ◽  
Mass Spectrometers ◽  
Organic Mixtures ◽  
Ideal Technique

Mass spectrometers can provide information about molecular composition and chemical structure. However, with complex mixtures, superpositions and even suppression of signals may occur. On the other hand, Chromatography is an ideal technique for separating complexes but is often insufficient for compound identification. Hence, coupling both techniques in order to eliminate the limitations of each technique makes perfect sense. In this contribution, a brief description of mass spectrometry coupled with chromatography in the gas and liquid phase will be discussed to explain the advantages of coupling the two methods. The ionization techniques are also reported and followed by application areas of these techniques. Finally, the recording and treatment of the results are reviewed.

Réactions ion/molécule de l'ion C2H3Cl+ dans le mélange gazeux: chlorure de vinyle – chlorure d'éthyle

1989 ◽  
Vol 67 (1) ◽  
pp. 97-103 ◽  
Author(s):  
Jan A. Herman ◽  
Rodica Neagu-Plesu ◽  
Leszek Wójcik
Keyword(s):  
Mass Spectrometry ◽  
High Pressure ◽  
Vinyl Chloride ◽  
Ethyl Chloride ◽  
The Other ◽  
Mass Spectrometers ◽  
Condensation Reactions ◽  
Ion Molecule Reactions ◽  
Photo Ionization

Ion/molecule reactions of C2H3Cl+ have been studied in a mixture of vinyl and ethyl chlorides. The ionic processes have been followed using two mass spectrometers; one is based on the ionic cyclotronic resonance (ICR) while the other is based on photo-ionization at high pressure. The results obtained on these two instruments are complementary and they indicate that the ion C2H3Cl+ does not react directly with ethyl chloride. However, the ions C4H3Cl+ and C4H6Cl+, which are formed following the decomposition of the excited ion-dimer of vinyl chloride, do react with ethyl chloride in a series of condensation reactions involving in each step an elimination of HCl or of Cl. In a mixture of the two chlorides, the most important ions are the C8H13+ and C8H14+; at a pressure of 1 Tonr, their total intensity is equal to 50%. Keywords: ion/molecule reactions of C2H3Cl+, vinyl and ethyl chloride mixtures, mass spectrometry. [Journal translation]

The Reactivity of Different Active Forms of Sodium Carbonate with Respect to Sulfur Dioxide

1992 ◽  
Vol 57 (11) ◽  
pp. 2302-2308
Author(s):  
Karel Mocek ◽  
Erich Lippert ◽  
Emerich Erdös
Keyword(s):  
Thermal Decomposition ◽  
Liquid Phase ◽  
Sulfur Dioxide ◽  
Specific Surface ◽  
Surface Area ◽  
Sodium Carbonate ◽  
Room Temperature ◽  
Active Form ◽  
The Other ◽  
Kinetics Of

The kinetics of the reaction of solid sodium carbonate with sulfur dioxide depends on the microstructure of the solid, which in turn is affected by the way and conditions of its preparation. The active form, analogous to that obtained by thermal decomposition of NaHCO3, emerges from the dehydration of Na2CO3 . 10 H2O in a vacuum or its weathering in air at room temperature. The two active forms are porous and have approximately the same specific surface area. Partial hydration of the active Na2CO3 in air at room temperature followed by thermal dehydration does not bring about a significant decrease in reactivity. On the other hand, if the preparation of anhydrous Na2CO3 involves, partly or completely, the liquid phase, the reactivity of the product is substantially lower.

scholarly journals Polyphenol Profiling of Chestnut Pericarp, Integument and Curing Water Extracts to Qualify These Food By-Products as a Source of Antioxidants

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2335
Author(s):  
Gabriella Pinto ◽  
Sabrina De Pascale ◽  
Maria Aponte ◽  
Andrea Scaloni ◽  
Francesco Addeo ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Negative Impact ◽  
Tap Water ◽  
Time Of Flight ◽  
The Other ◽  
Curing Process ◽  
Flight Mass Spectrometry ◽  
Water Curing ◽  
The Impact ◽  
By Products

Plant polyphenols have beneficial antioxidant effects on human health; practices aimed at preserving their content in foods and/or reusing food by-products are encouraged. The impact of the traditional practice of the water curing procedure of chestnuts, which prevents insect/mould damage during storage, was studied to assess the release of polyphenols from the fruit. Metabolites extracted from pericarp and integument tissues or released in the medium from the water curing process were analyzed by matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) and electrospray-quadrupole-time of flight-mass spectrometry (ESI-qTOF-MS). This identified: (i) condensed and hydrolyzable tannins made of (epi)catechin (procyanidins) and acid ellagic units in pericarp tissues; (ii) polyphenols made of gallocatechin and catechin units condensed with gallate (prodelphinidins) in integument counterparts; (iii) metabolites resembling those reported above in the wastewater from the chestnut curing process. Comparative experiments were also performed on aqueous media recovered from fruits treated with processes involving: (i) tap water; (ii) tap water containing an antifungal Lb. pentosus strain; (iii) wastewater from a previous curing treatment. These analyses indicated that the former treatment determines a 6–7-fold higher release of polyphenols in the curing water with respect to the other ones. This event has a negative impact on the luster of treated fruits but qualifies the corresponding wastes as a source of antioxidants. Such a phenomenon does not occur in wastewater from the other curing processes, where the release of polyphenols was reduced, thus preserving the chestnut’s appearance. Polyphenol profiling measurements demonstrated that bacterial presence in water hampered the release of pericarp metabolites. This study provides a rationale to traditional processing practices on fruit appearance and qualifies the corresponding wastes as a source of bioactive compounds for other nutraceutical applications.

Compositional Analysis of Organosolv Poplar Lignin by Using High-Performance Liquid Chromatography/High-resolution Multi-stage Tandem Mass Spectrometry

2021 ◽  
Author(s):  
Jifa Zhang ◽  
Yuan Jiang ◽  
Leah F Easterling ◽  
Anton Anster ◽  
Wanru Li ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Compositional Analysis ◽  
Complex Mixtures ◽  
Tandem Mass ◽  
Multi Stage ◽  
The Individual ◽  
Environmentally Friendly Process

Organosolv treatment is an efficient and environmentally friendly process to degrade lignin into small compounds. The capability of characterizing the individual compounds in the complex mixtures formed upon organosolv treatment...

scholarly journals Benchmarking Non-Targeted Metabolomics Using Yeast-Derived Libraries

Metabolites ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 160
Author(s):  
Evelyn Rampler ◽  
Gerrit Hermann ◽  
Gerlinde Grabmann ◽  
Yasin El Abiead ◽  
Harald Schoeny ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Quality Control ◽  
Protein Identification ◽  
Regulatory Elements ◽  
Yeast Fermentation ◽  
Compound Identification ◽  
Targeted Metabolomics ◽  
Targeted Analysis ◽  
Orthogonal State ◽  
Starting Point

Non-targeted analysis by high-resolution mass spectrometry (HRMS) is an essential discovery tool in metabolomics. To date, standardization and validation remain a challenge. Community-wide accepted cost-effective benchmark materials are lacking. In this work, we propose yeast (Pichia pastoris) extracts derived from fully controlled fermentations for this purpose. We established an open-source metabolite library of >200 identified metabolites based on compound identification by accurate mass, matching retention times, and MS/MS, as well as a comprehensive literature search. The library includes metabolites from the classes of (1) organic acids and derivatives (2) nucleosides, nucleotides, and analogs, (3) lipids and lipid-like molecules, (4) organic oxygen compounds, (5) organoheterocyclic compounds, (6) organic nitrogen compounds, and (7) benzoids at expected concentrations ranges of sub-nM to µM. As yeast is a eukaryotic organism, key regulatory elements are highly conserved between yeast and all annotated metabolites were also reported in the human metabolome database (HMDB). Orthogonal state-of-the-art reversed-phase (RP-) and hydrophilic interaction chromatography mass spectrometry (HILIC-MS) non-targeted analysis and authentic standards revealed that 104 out of the 206 confirmed metabolites were reproducibly recovered and stable over the course of three years when stored at −80 °C. Overall, 67 out of these 104 metabolites were identified with comparably stable areas over all three yeast fermentation and are the ideal starting point for benchmarking experiments. The provided yeast benchmark material enabled not only to test for the chemical space and coverage upon method implementation and developments but also allowed in-house routines for instrumental performance tests. Transferring the quality control strategy of proteomics workflows based on the number of protein identification in HeLa extracts, metabolite IDs in the yeast benchmarking material can be used as metabolomics quality control. Finally, the benchmark material opens new avenues for batch-to-batch corrections in large-scale non-targeted metabolomics studies.

scholarly journals Measurement of δ18O and δ2H of water and ethanol in wine by Off-Axis Integrated Cavity Output Spectroscopy and Isotope Ratio Mass Spectrometry

2021 ◽  
Author(s):  
Xing Wang ◽  
Henk G. Jansen ◽  
Haico Duin ◽  
Harro A. J. Meijer
Keyword(s):  
Mass Spectrometry ◽  
Isotope Ratio ◽  
Isotope Analysis ◽  
Isotope Ratio Mass Spectrometry ◽  
Growth Conditions ◽  
The Other ◽  
H Nmr ◽  
Cavity Output ◽  
Pre Treatment ◽  
Output Laser

AbstractThere are two officially approved methods for stable isotope analysis for wine authentication. One describes δ18O measurements of the wine water using Isotope Ratio Mass Spectrometry (IRMS), and the other one uses Deuterium-Nuclear Magnetic Resonance (2H-NMR) to measure the deuterium of the wine ethanol. Recently, off-axis integrated cavity output (laser) spectroscopy (OA-ICOS) has become an easier alternative to quantify wine water isotopes, thanks to the spectral contaminant identifier (SCI). We utilized an OA-ICOS analyser with SCI to measure the δ18O and δ2H of water in 27 wine samples without any pre-treatment. The OA-ICOS results reveal a wealth of information about the growth conditions of the wines, which shows the advantages to extend the official δ18O wine water method by δ2H that is obtained easily from OA-ICOS. We also performed high-temperature pyrolysis and chromium reduction combined with IRMS measurements to illustrate the “whole wine” isotope ratios. The δ18O results of OA-ICOS and IRMS show non-significant differences, but the δ2H results of both methods differ much more. As the δ2H difference between these two methods is mainly caused by ethanol, we investigated the possibility to deduce deuterium of wine ethanol from this difference. The results present large uncertainties and deviate from the obtained 2H-NMR results. The deviation is caused by the other constituents in the wine, and the uncertainty is due to the limited precision of the SCI-based correction, which need to improve to obtain the 2H values of ethanol as alternative for the 2H-NMR method.

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