Tandem Mass Spectrometry (MS/MS) for Analysis of Organic Additives in an Uncured Rubber Compound

1990 ◽  
Vol 63 (2) ◽  
pp. 298-307 ◽  
Author(s):  
R. P. Lattimer ◽  
H. Muenster ◽  
H. Budzikiewicz
Keyword(s):  
Mass Spectrometry ◽  
Direct Analysis ◽  
Molecular Ions ◽  
The Other ◽  
Ion Current ◽  
Diagnostic Tools ◽  
Ion Currents ◽  
Rubber Compound ◽  
Organic Additives ◽  
Other Hand

Abstract In this study, we examined the feasibility of obtaining MS/MS data for organic additives in an uncured rubber compound using several different ionization methods. EI-MS/MS worked well for those additives that gave intense molecular ions (M+·) via this mode of ionization. CI-MS/MS also worked quite well for most additives; the CI MH+ ion currents were generally quite intense and stable over a long period of time. Although fragmentation patterns for MH+ ions are different from those obtained from M+· ions, the fragments are still good diagnostic tools for identifying the original molecule. On the other hand, the FI- and FD-MS/MS analyses of these rubber samples were generally not very satisfactory. This was due to the fact that FI/FD ion currents were too weak and unstable to give daughter-ion spectra with good S/N. It may be concluded that the best way to detect and identify typical organic additives in a compounded rubber is to use a combination of EI- and CI-MS/MS. In this study, intact accelerators were successfully analyzed by MS/MS. The two accelerators in this particular rubber (OBTS and DPG) could be confirmed quite readily by daughter-ion analysis of their intense MH+ ions (CI-MS/MS). Daughter-ion analyses of M+· obtained by either EI, FI or FD modes were not very successful, however. In EI, the difficulty is that molecular ions are quite weak (or even absent) for typical rubber curatives. In FI and FD, on the other hand, a very large proportion of the ion current for accelerators resides in the molecular ion. The difficulty here is that the total ion current produced by FI or FD is rather low. The MS/MS approach has proven to be very useful for direct analysis of organic additives in rubber compounds. The principal advantage in using MS/MS is that more information is available from mixtures than can be obtained by direct analysis using conventional mass spectral methods. The MS/MS technique is also rapid experimentally compared to other techniques for mixture analysis such as GC/MS, LC/MS, or high resolution (AC-MS). Finally, since MS/MS involves two stages of mass analysis, it leads to a great reduction in the chemical noise associated with single-stage mass spectrometry. This leads to the facile confirmation of the presence (or absence) of specific components in a complex mixture.

Cell and Tissue Imaging by TOF-SIMS and MALDI-TOF: An Overview for Biological and Pharmaceutical Analysis

2021 ◽  
pp. 1-26
Author(s):  
Manale Noun ◽  
Rayane Akoumeh ◽  
Imane Abbas
Keyword(s):  
Mass Spectrometry ◽  
Spatial Distribution ◽  
Time Of Flight ◽  
Molecular Ions ◽  
Tissue Imaging ◽  
Diagnostic Tools ◽  
Good Precision ◽  
Maldi Tof ◽  
Tof Sims ◽  
Wide Range

Abstract The potential of mass spectrometry imaging (MSI) has been demonstrated in cell and tissue research since 1970. MSI can reveal the spatial distribution of a wide range of atomic and molecular ions detected from biological sample surfaces, it is a powerful and valuable technique used to monitor and detect diverse chemical and biological compounds, such as drugs, lipids, proteins, and DNA. MSI techniques, notably matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) and time of flight secondary ion mass spectrometry (TOF-SIMS), witnessed a dramatic upsurge in studying and investigating biological samples especially, cells and tissue sections. This advancement is attributed to the submicron lateral resolution, the high sensitivity, the good precision, and the accurate chemical specificity, which make these techniques suitable for decoding and understanding complex mechanisms of certain diseases, as well as monitoring the spatial distribution of specific elements, and compounds. While the application of both techniques for the analysis of cells and tissues is thoroughly discussed, a briefing of MALDI-TOF and TOF-SIMS basis and the adequate sampling before analysis are briefly covered. The importance of MALDI-TOF and TOF-SIMS as diagnostic tools and robust analytical techniques in the medicinal, pharmaceutical, and toxicology fields is highlighted through representative published studies.

scholarly journals Mass Spectrometry-Based Characterization of New Spirolides from Alexandrium ostenfeldii (Dinophyceae)

Marine Drugs ◽  
2020 ◽  
Vol 18 (10) ◽  
pp. 505
Author(s):  
Joyce A. Nieva ◽  
Jan Tebben ◽  
Urban Tillmann ◽  
Sylke Wohlrab ◽  
Bernd Krock
Keyword(s):  
Mass Spectrometry ◽  
High Resolution Mass Spectrometry ◽  
Molecular Ions ◽  
Ring System ◽  
The Other ◽  
Spectral Techniques ◽  
Mass Spectral ◽  
Alexandrium Ostenfeldii ◽  
Different Strains

Spirolides belong to a group of marine phycotoxins produced by the marine planktonic dinophyte Alexandrium ostenfeldii. Composed of an imine moiety and a spiroketal ring system within a macrocylcle, spirolides are highly diverse with toxin types that vary among different strains. This study aims to characterize the spirolides from clonal A. ostenfeldii strains collected from The Netherlands, Greenland and Norway by mass spectral techniques. The structural characterization of unknown spirolides as inferred from high-resolution mass spectrometry (HR-MS) and collision induced dissociation (CID) spectra revealed the presence of nine novel spirolides that have the pseudo-molecular ions m/z 670 (1), m/z 666 (2), m/z 696 (3), m/z 678 (4), m/z 694 (5), m/z 708 (6), m/z 720 (7), m/z 722 (8) and m/z 738 (9). Of the nine new spirolides proposed in this study, compound 1 was suggested to have a truncated side chain in lieu of the commonly observed butenolide ring in spirolides. Moreover, there is indication that compound 5 might belong to new spirolide subclasses with a trispiroketal ring configuration having a 6:5:6 trispiroketal ring system. On the other hand, the other compounds were proposed as C- and G-type SPX, respectively. Compound 7 is proposed as the first G-type SPX with a 10-hydroxylation as usually observed in C-type SPX. This mass spectrometry-based study thus demonstrates that structural variability of spirolides is larger than previously known and does not only include the presence or absence of certain functional groups but also involves the triketal ring system.

Sin and Self-Functioning, Part 3: The Psychology and Ideology of Irrational Beliefs

1988 ◽  
Vol 16 (4) ◽  
pp. 348-361 ◽  
Author(s):  
P.J. Watson ◽  
Ronald J. Morris ◽  
Ralph W. Hood
Keyword(s):  
Irrational Beliefs ◽  
World View ◽  
Direct Analysis ◽  
The Other ◽  
Religious Motivation ◽  
Irrational Thinking ◽  
Other Hand ◽  
Rational Emotive ◽  
Positive Correlations

Irrational beliefs identified by Rational-Emotive theory (Ellis, 1962) as pathogenic were related to religious motivations and to orthodox beliefs having to do with sin. An extrinsic religious motivation and beliefs referring to the guilt of others appeared to predict problematic self-functioning. On the other hand, intrinsicness and beliefs about grace displayed complex linkages with irrational thinking and were also associated with less depression. A direct analysis of how subjects evaluated specific beliefs relative to their religious commitments suggested that positive correlations of intrinsicness and of grace with at least some irrational beliefs may not be indicative of true “irrationality.” Instead, religious individuals may be reasoning from a world view that is ideologically incompatible with Rational-Emotive theory.

scholarly journals Real-time monitoring of the reaction between aniline and acetonylacetone using extractive electorspray ionization tandem mass spectrometry

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Xinglei Zhang ◽  
Miaorong Pei ◽  
Debo Wu ◽  
Shuiping Yang ◽  
Zhanggao Le
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Real Time ◽  
Sample Pretreatment ◽  
Direct Analysis ◽  
Molecular Ions ◽  
Tandem Mass ◽  
Monitoring Method ◽  
On Line ◽  
Ionization Tandem Mass Spectrometry

AbstractIn this work an on-line monitoring method was developed to study the mechanism of acetic acid catalyzed reaction between aniline and acetonylacetone using extractive electorspray ionization-tandem mass spectrometry (EESI-MS). The signals of reactants, intermediates and various byproducts were continuously detected as a function of reaction time. The chemical assignment of each signal was done via multi-stage collision induced dissociation (CID) analysis, and the reaction mechanism between aniline and acetonylacetone was deduced based on the generated molecular ions and fragment ions. The results indicate that on-line EESI-MS is an effective technique for the real time analysis of chemical reactions. EESI avoids off-line sample pretreatment and provides “soft” ionization, which allows direct analysis of various analytes at molecular level.

First Detection of Tetrodotoxin in the Bivalve Paphies australis by Liquid Chromatography Coupled to Triple Quadrupole Mass Spectrometry With and Without Precolumn Reaction

2014 ◽  
Vol 97 (2) ◽  
pp. 325-333 ◽  
Author(s):  
Paul S McNabb ◽  
David I Taylor ◽  
Shaun C Ogilvie ◽  
Larn Wilkinson ◽  
Alice Anderson ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Direct Analysis ◽  
The Other ◽  
Marine Biota ◽  
Triple Quadrupole ◽  
Quadrupole Mass ◽  
Laboratory Trial ◽  
Single Laboratory

Abstract Two methods for the determination of tetrodotoxin(TTX) in marine biota have been developed and validated using ultra-performance LC coupled to triple quadrupole MS. The direct analysis of TTX is completed in one method, while the other method detects the dehydration product of TTX after reaction with base. The methods were validated in a single-laboratory trial and used to test Paphies australis (pipi) samples collected from Whangapoua, New Zealand during April 2011. Pa. australis is a commonly eaten species of bivalve that was found to contain TTX at levels up to 0.80 mg/kg in this study. The methods exhibited recoveries ranging from 94 to 120%, and the within laboratory reproducibility ranged from 6 to 27% for Pleurobranchaea maculata (grey-side gilled sea slug) andbivalve matrixes. Use of the method using a dehydration step showed no evidence of TTX analogs in any ofthe samples.

scholarly journals Cardiometabolic Diseases: Biochemistry, Pathophysiology and Medical Innovations

2020 ◽  
pp. 1-5
Author(s):  
Gundu Rao
Keyword(s):  
Medical School ◽  
Cell Biology ◽  
Metabolic Diseases ◽  
Medical Science ◽  
Medical Knowledge ◽  
Vascular Diseases ◽  
The Other ◽  
Diagnostic Tools ◽  
Cardiometabolic Diseases ◽  
Other Hand

It gives us great pleasure, to write this invited overview on, Biochemistry, pathophysiology and Medical Innovations, to the Journal of Biochemistry and Modern Applications. In an earlier article on a similar topic, we described a biochemistry course, that is offered at the Cambridge University UK, called The Molecules in Medical Science, which focuses on diseases, that are familiar by name and of high relevance like diabetes and cancer. Harvard Medical School, on the other hand, says, preparation of medical school in the 21st century, should reflect contemporary developments in medical knowledge, the pace of discovery and the permeation of biochemistry, cell biology, and genetics into most areas of medicine. Oxford Royale Academy looks at biomedicine the following way; -Biochemistry, as the name suggests, is where Biology meets Chemistry: it is the study of the living things, at a molecular level- or, to put it another way, the study of the very foundations of life. On the other hand, pathophysiology deals with a variety of altered metabolism, which drives the normal physiology out of gear, and promotes the development of risks, for various metabolic diseases. The Cardiometabolic Syndrome represents a constellation of metabolic abnormalities that are risk factors for the development of metabolic diseases, which in turn promote vascular diseases. Major metabolic diseases include hypertension, excess weight, obesity, and type-2 diabetes. Vascular diseases remain the number one killer worldwide and have retained this status for over a century. There is considerable debate, about whether the treatment of the disease itself is superior, or just the management of observed risks is enough? In view of such debates, there is a great need for the development of technologies that will facilitate early diagnosis and better management of progression, or regression of diseases. Furthermore, advances in research in the fields of genetics, cellular biology, molecular biology, and emerging diagnostic tools, will improve our ability to manage chronic cardiometabolic diseases. In this overview, we have discussed advances in the various fields, the disconnect that exists between the researchers and clinicians, as well as between technologists and the end-users.

Analysis of Components in Rubber Compounds Using Mass Spectrometry

1989 ◽  
Vol 62 (3) ◽  
pp. 548-567 ◽  
Author(s):  
Robert P. Lattimer ◽  
Robert E. Harris
Keyword(s):  
Mass Spectrometry ◽  
High Sensitivity ◽  
High Specificity ◽  
Mass Spectrometric ◽  
Rubber Compound ◽  
Organic Additives ◽  
Mixture Analysis ◽  
Rubber Compounds ◽  
Invaluable Tool ◽  
Modern Mass

Abstract A large number of very successful mass-spectrometric methods have been developed for rubber-compound analysis. The high sensitivity, high specificity, and superb mixture analysis capabilities of modern mass spectrometry make it an invaluable tool in the polymer industry, particularly for qualitative identification of organic additives. In many cases, mass spectrometry can provide unique information that is not available by use of any other technique.

Identification of Organic Components in Uncured Rubber Compounds Using Mass Spectrometry

1988 ◽  
Vol 61 (4) ◽  
pp. 639-657 ◽  
Author(s):  
R. P. Lattimer ◽  
R. E. Harris ◽  
C. K. Rhee ◽  
H-R. Schulten
Keyword(s):  
Mass Spectrometry ◽  
Organic Additive ◽  
Molecular Ions ◽  
Organic Additives ◽  
Additional Information ◽  
Filled Rubber ◽  
Rubber Compounds ◽  
Surface Desorption ◽  
Direct Thermal Desorption ◽  
Ionization Methods

Abstract Three carbon-black-filled rubber compounds of known composition were analyzed by mass spectrometry. Direct thermal desorption was used with three different methods of ionization (EI, CI, FI). In addition, the three rubbers were examined by FAB-MS (without liquid matrix) as a means for surface desorption/ionization. Extracts of the rubbers were also examined using two different solvents (acetone and acetonitrile). Each extract was examined directly by five methods of ionization (EI, CI, FI, FD, FAB). Of the various vaporization/ionization methods, it appears that FI/FD is the most efficient for identifying typical organic additives in rubber stocks. The analysis can be carried out using either the untreated rubber (FI mode) or else a solvent extract (FD mode). Molecular ions are dominant, which facilitates the characterization of the complex organic additive mixtures that are present in typical compounded rubbers. For samples in which the identity of FD/FI molecular ions is unclear, further analysis using other methods (EI, CI, FAB, MS/MS, GC/MS, LC/MS, high resolution) can be carried out to gain additional information. We conclude that FD and FI yield the most useful information in the shortest period of time. The main difference between the results of this study and those of the volcanizate study is with respect to the curatives. Intact accelerator molecules could readily be observed in the spectra from the uncured stocks, while only accelerator fragments could be observed from the vulcanizates.

Direct Analysis of Spectra by Image Isocon and Computer

1971 ◽  
Vol 11 ◽  
pp. 86-89
Author(s):  
G. A. H. Walker ◽  
J. R. Auman ◽  
V. Buchholz ◽  
B. Goldberg ◽  
B. Isherwood
Keyword(s):  
Quantum Efficiency ◽  
Spatial Resolution ◽  
Dynamic Range ◽  
Direct Analysis ◽  
The Other ◽  
Digital Form ◽  
Other Hand ◽  
Imaging Detectors ◽  
Photographic Emulsions ◽  
Reciprocity Failure

Astronomical spectra are, with few exceptions, still being recorded on photographic emulsions. These generally have the advantages of better spatial resolution and larger available area than existing photoelectric imaging detectors. On the other hand they do suffer from a small dynamic range (15 or 20: 1), reciprocity failure, and a quantum efficiency of less than 1 per cent. Image intensifiers and image orthocons can be used to improve sensitivity, but where photographs are used for the record the other problems tend to remain. Calibration and extraction of the appropriate astronomical information in digital form involves a considerable amount of time and careful work, as one can appreciate from many of the papers presented at this colloquium.

scholarly journals Investigation of a Chinese Ink Rubbing by 14C AMS Analysis

Radiocarbon ◽  
2003 ◽  
Vol 45 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Hong-Chien Yuan ◽  
Walter Kutschera ◽  
Tze-Yue Lin ◽  
Peter Steier ◽  
Christof Vockenhuber ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Comparative Study ◽  
Accelerator Mass Spectrometry ◽  
Confidence Limit ◽  
Sem Analysis ◽  
The Other ◽  
Chinese Characters ◽  
Other Hand ◽  
Art Objects ◽  
Scanning Electron

The date of a Chinese ink rubbing was determined using radiocarbon accelerator mass spectrometry (AMS) to be in the range from AD 1480 to AD 1670 (95.4% confidence limit). Together with a scanning electron miscroscope (SEM) analysis of the ink and a comparative study of the Chinese characters, it was determined that the ink rubbing must have been performed before Emperor Kang Hsi (AD 1662–1722), who ruled at the beginning of the Chin Dynasty. On the other hand, the stone stele, from which the ink rubbing was produced, was carved in AD 531, which is consistent with an analysis of some erased characters. Such analysis seems to be useful to help clarify possible forgeries of these art objects.

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