Phytochemical and Bioactive Potential of Melastoma malabathricum: an Important Medicinal Herb
V. R. Mohan, A. Doss, P. S. Tresina in Ethnomedicinal Plants with Therapeutic Properties, 2019
Gas chromatography-mass spectrometry (GC–MS) is an analytical method that combines the features of gas chromatography and mass spectrometry to identify different substances within a test sample applications of GC–MS include drug detection, fire investigation, environmental analysis, explosives investigation, and identification of unknown samples, including that of material samples obtained from planet Mars during probe missions as early as the 1970s. GC–MS can also be used in airport security to detect substances in luggage or on human beings. Additionally, it can identify trace elements in materials that were previously thought to have disintegrated beyond identification. Like liquid chromatography–mass spectrometry, it allows analysis and detection even for the tiny amounts of a substance (David Sparkman et al., 2011).
Protein/Peptide Sequence Analysis by Mass Spectrometry
Ajit S. Bhown in Protein/Peptide Sequence Analysis: Current Methodologies, 1988
Within the broad area of mass spectrometry exists a variety of methodologies that can be applied to the molecular analysis of polypeptides and proteins. This chapter will present an overview of the procedures available to the mass spectroscopist for these analyses. For organizational purposes, the subject will be divided into topics related to the means of introducing the sample into the mass spectrometer. During these discussions, references to detailed descriptions of each technique will be cited so the reader can gain additional information about the subject at hand if so desired. First to be covered will be direct probe introduction of samples to be analyzed. Fast atom bombardment (FAB) and other desorbtion techniques will be discussed here. Second to be described will be applications using liquid chromatography-mass spectrometry (LC-MS) techniques. Third, the use of gas chromato-graphy-mass spectrometry (GC-MS) for polypeptide sequence analysis will be presented and the oligiopeptide reduction-trimethylsilylation and dipeptidyl peptidase methodologies will be described.
Liquid Biopsies for Pancreatic Cancer: A Step Towards Early Detection
Surinder K. Batra, Moorthy P. Ponnusamy in Gene Regulation and Therapeutics for Cancer, 2021
Generally, Gas Chromatography-Mass Spectrometry (GC-MS), Liquid Chromatography-Mass Spectrometry (LC-MS), Capillary Electrophorese-Mass Spectrometry (CE-MS), Fourier Transform Ion Cyclotron Resonance-Mass Spectrometry (FTICR-MS), Nuclear Magnetic Resonance (NMR) and High Resolution Magic Angle Spinning Nuclear Magnetic Spectroscopy (HR-MAS-NMR) are used for metabolic profiling from biological specimens. These techniques have their own advantages/ disadvantages but data acquired by each separate modality complement one another [42, 43]. Also, due to the technical difficulties, hydrophilic and hydrophobic metabolites have not yet been able to be analyzed using a single technique. Thus, for obtaining a robust and global metabolite profile of the patient and in order to discern the disease versus normal states, a combination of various analytical techniques is used [43]. Recent advances in the field have enabled metabolites to be visualized spatially within biological samples using imaging mass spectrometry [44].
Association between coronary artery vitamin D receptor expression and select systemic risks factors for coronary artery atherosclerosis
Published in Climacteric, 2022
M. Nudy, R. Xie, D. M. O’Sullivan, X. Jiang, S. Appt, T. C. Register, J. R. Kaplan, T. B. Clarkson, P. F. Schnatz
Plasma (500 μl) was collected from all cynomolgus monkeys (n = 39) at three time points (baseline, time of menopause and necropsy). Frozen samples (−70 °C) were packaged such that they were protected from direct sunlight and transported to Reading Hospital, Reading, PA, USA [21,24]. The samples had never been thawed before the 25OHD measurements were performed. High performance liquid chromatography/tandem mass spectrometry utilizing Shimadzu liquid chromatography–mass spectrometry/mass spectrometry technology was used for 25OHD determination. Liquid chromatography–mass spectrometry allows for sample ionization, through the physical separation abilities of liquid chromatography, for mass analysis with the AB Sciex 3200 Q Trap mass spectrometer. The 25OHD was measured at necropsy.
Accuracy of substance exposure history in patients attending emergency departments after substance misuse; a comparison with biological sample analysis
Published in Clinical Toxicology, 2023
Ishita Virmani, Alberto Oteo, Michael Dunn, Daniel Vidler, Clair Roper, Jane Officer, Gareth Hardy, Paul I. Dargan, Michael Eddleston, Jamie G. Cooper, Simon L. Hill, Rebecca Macfarlane, Liza Keating, Mark Haden, Simon Hudson, Simon H. L. Thomas
Toxicity resulting from substance misuse (sometimes called recreational drug use/misuse) is a common reason for emergency department (ED) presentations and hospital admissions [1,2]. Knowledge of the substances involved helps to interpret clinical features, anticipate the predicted clinical course, and inform appropriate monitoring and management decisions, including in some cases the administration of antidotes. Urine drug screening using immunoassays is sometimes performed, but has substantial limitations, including low sensitivity and specificity and, in particular, may not detect new psychoactive substances (NPS) [3], although methods have been developed to detect some specific compounds [4]. While liquid chromatography-mass spectrometry can be very sensitive for detecting substances of misuse, it is time consuming and expensive to perform. As a result, real-time analytical information is rarely available at the time of presentation, so the history provided by the patient or other witnesses is often the only source of information on substances involved. Research and surveillance studies of reported substance use, important for developing national drug control policies [5], may also rely on unvalidated user accounts for exposure information.
Soyasaponin I alleviates hypertensive intracerebral hemorrhage by inhibiting the renin–angiotensin–aldosterone system
Published in Clinical and Experimental Hypertension, 2023
Wei Li, Shao-Guang Li, Lan Li, Li-Jian Yang, Zeng-Shi Li, Xi Li, An-Yuan Ye, Yang Xiong, Yi Zhang, Yuan-Yuan Xiong
Samples were first dissolved and extracted using methanol. Equal amounts were taken from all samples and then mixed as quality control (QC) samples. Liquid chromatography–mass spectrometry (LC–MS) analysis was performed on a high-performance liquid chromatograph (#AB ExionLC, AB Sciex, USA) and a high-resolution mass spectrometer (#QE, ThermoFisher, USA). The chromatographic column was ACQUITY UPLC BEH C18 (100 mm × 2.1 mm, 1.7 μm, Waters, USA) with the column temperature set at 40°C. The mobile phase A was water (containing 0.1% formic acid), the mobile phase B was acetonitrile (containing 0.1% formic acid), and the flow rate was set at 0.35 mL/min with an injection volume of 5 μL. The gradient elution program was as follows: 0 min A:B = 95:5; 1.5 min A:B = 95:5; 3 min A:B = 70:30; 7 min A:B = 40:60; 9 min A:B = 10:90; and 11 min A:B = 10:90. The MS signal acquisition was performed in positive and negative ion scan mode, and the MS parameters were set as follows: spray voltage, 3500 V; capillary temperature, 320°C; probe heater temperature, 350°C; sheath gas flow rate, 40 Arb; auxillary gas flow rate, 10 Arb; S-lens RF level, 50; mass range, 100–1000 m/z. Finally, metabolomic analysis of LC–MS data was commissioned from Shanghai Lu-Ming Biotech Co., Ltd.
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