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Mass Spectrometric Analysis
Published in Adorjan Aszalos, Modern Analysis of Antibiotics, 2020
Mass spectrometry is capable of providing considerable analytical information in antibiotic research. Its most fundamental use is to determine the molecular weight of an unknown. When this is done at high resolution the elemental composition is also obtained. This can be done with smaller and less pure samples than are required for conventional elemental analysis. Ionization methods use energy sources that cause various degrees of molecular decomposition. Detection of the charged products from these reactions provides strong evidence for structural features. Further information may be obtained from mass spectral data obtained before and after chemical derivatization or isotope exchange. Indeed, structural identifications are possible from mass spectral data alone. In addition to identifying new antibiotics, mass spectrometry has been useful for identifying antibiotics modified by chemical synthesis, fermentation changes, and metabolism. When interfaced with a chromatographic method, as with liquid chromatography-mass spectrometry, crude fermentation broths can be screened for specific antibiotics or the components of an antibiotic mixture can be determined. In addition, quantitative analysis with high sensitivity are possible.
Use of Computers in Radiotracer Studies
Published in Lelio G. Colombetti, Principles of Radiopharmacology, 2019
A particularly valuable use of a gamma ray peak searching computer program is in neutron activation analysis. The computer can calculate the counts in each peak and therefore the microcuries of each isotope present. The computer can type out the micrograms of each element, if calibration factors such as the neutron flux and counts from flux monitoring samples are typed into the computer. Thus in summary, a computer-controlled ADC can be used to acquire spectra from neutron activation samples, and the computer can compare the spectrum with data stored on magnetic disk, and finally print out the number of micrograms of each element in the sample. The time required to print out the elemental analysis will depend only upon the speed at which the printer can print. The computer program could use several isotopes from a single element as a confirmation check, and could also print out the isotopic ratios.
Technetium-Labeled Compounds
Published in Garimella V. S. Rayudu, Lelio G. Colombetti, Radiotracers for Medical Applications, 2019
Suresh C. Srivastava, Powell Richards
It should be noted that the compounds included in Table 11 are the ones on which X-ray structural information is available. A number of technetium complexes, other than those described in this table, have been prepared and studied recently. The ligands used include 2,4-pentanedione(acetylacetone),196,197 EDTA,198 cyclam,199 nitrosyl,200HIDA,201-202 various porphyrins,202 aminothiol,203 aminopolycarboxylates,197,204 thiol-ate,205 NTA,206 EHDP,207 and others. Most of these compounds were prepared without the use of stannous ion as a reducing agent, mainly by starting with well defined pre-reduced technetium compounds as starting materials. Techniques used for characterization include elemental analysis, UV, visible, and IR spectra, NMR, ESR, etc.
Comparison of clinical efficacy of three different dentin matrix biomaterials obtained from different devices
Published in Expert Review of Medical Devices, 2023
Robert Dłucik, Bogusława Orzechowska-Wylęgała, Daniel Dłucik, Domenico Puzzolo, Giuseppe Santoro, Antonio Micali, Barbara Testagrossa, Giuseppe Acri
One part of each control teeth and the crushed particles obtained from BonMaker, Tooth Transformer, and Smart Dentin Grinder devices, all treated as above indicated for SEM, were air-dried, mounted on aluminum stubs, and examined for elemental analysis by the energy-dispersive X-Ray analyzer (EDX) Jeol DX200s (JEOL, Tokyo, Japan). An X-ray spectrum was obtained, and the elements from each specimen were identified from the peak energy and quantitatively analyzed from the intensity of the peaks. The results were obtained by referring to the energy spectra of calibration included in the instrument library. The qualitative and quantitative elemental analyses were performed at different points of the surface of each sample, and the obtained results were related to the mean value of the measurements.
The effects of a new antidiabetic glycinium [(pyridine-2, 6-dicarboxylato) oxovanadate (V)] complex in high-fat diet of streptozotocin-induced diabetic rats
Published in Archives of Physiology and Biochemistry, 2022
Gholamreza Komeili, Fatemeh Ghasemi, Ali Reza Rezvani, Khaled Ghasemi, Farzaneh Khadem Sameni, Mohammad Hashemi
Synthesis of oxovanadate (V) compound, glycinium [(pyridine-2,6-dicarboxylato) oxovanadate (V)] complex was performed as described previously (Ghasemi et al. 2018). Briefly, 167 mg dipicolinic acid and 80 mg NaOH were dissolved in 20 mL the mixture of ethanol/water and dropwise added to 10 mL aqueous solution of VOSO4 (217 mg/mL). Subsequently, 37 mg glycine was added to the resulting mixture and refluxed for 48 h, filtered off and then left to evaporate in a beaker in air at the ambient temperature until colorless crystals were obtained. X-ray structural analysis was performed (Ghasemi et al. 2018). Elemental analyses were performed by using elemental analysis method (CHNS-932 elemental analyzer). The percentage of carbon, hydrogen and nitrogen obtained in this method (C, 32.87; H, 2.76; N, 8.78%), is consistent with precise elemental formula suggested by single-crystal X-ray diffraction analysis (C9H9N2O8V). Figure 1 shows the proposed structure of glycinium [(pyridine-2,6-dicarboxylato) oxovanadate (V)] complex.
Long-term stability test of elemental content in new environmental certified reference material candidates using ICP OES and ICP-SFMS
Published in Toxin Reviews, 2021
Abubakr M. Idris, Ahmed O. Alnajjar, Turki S. Alkhuraiji, Khaled F. Fawy
Elements present at macro-, micro- and trace-levels in various counterparts of the environment having both positive roles at controlled levels and negative effects at distorted levels (Ali et al. 2017a, 2017b, Ali et al. 2019, Idris 2019, Idris et al. 2019, Ashaiekh et al. 2019). Elemental analysis in different matrices is essential and has become more important due to environmental changes, ecological movements, biomedical science progress, rapid growth of international trade and introduction of international standards (Dybczyński and Polkowska-Motrenko 2016). Serious assessment and decisions in toxicological, environmental, medical, and nutritional fields are made depend on the results of chemical analyses including elements. Hence, the reliability of elemental analysis data is a critical issue.