Characterization of isomeric acetyl amino acids and di ‐acetyl amino acids by LC/MS/MS
In this study, it is aimed to synthesize and characterize all acetylated p roducts of natural α-amino acids. A total of 20 Nα-acetyl amino acids (1–20), six side-chain acetyl amino acids (21–26), and six diacetyl amino acids (27–32) were synthesized and characterized by liquid chromatography-electrospray ionizationtandem mass spectrometry (LC –ESI–MS/MS). The [M + H]+ ions of all the acetyl amino acids were subjected to MS/MS experiments to obtain their structural information. Apart from the expected loss of (H2O + CO) (immonium ions), most of the acetyl amino acids specifically showed loss of H2O and ...
Source: Journal of Mass Spectrometry - November 30, 2023 Category: Chemistry Authors: Addipilli Ramunaidu,
Pallerla Pavankumar,
Nagarjunachary Ragi,
Rodda Ramesh,
Medicharla V. Jagannatham,
Prabhakar Sripadi Tags: RESEARCH ARTICLE Source Type: research
Modelling some rod set imperfections of a quadrupole mass filter
AbstractThe problem of modeling the mass peak shape of a quadrupole mass filter (QMF) with round rods is considered. A number of factors leading to the degradation of the mass peak shape are studied, namely, displacement of the electrodes with respect to their original position, changes in the diameter of the electrodes, and asymmetry of the supply potentials. Decomposition of the rod set field on multipole fields allows to obtain an analytical representation of the ion motion equations. Simulations have shown that a parallel shift of one or two electrodes leads to a shift of the peak along the mass number axis and dips at...
Source: Journal of Mass Spectrometry - November 22, 2023 Category: Chemistry Authors: Pavel V. Bugrov,
Aleksey A. Sysoev,
Nikolai V. Konenkov Tags: RESEARCH ARTICLE Source Type: research
Further exploration of the collision ‐induced dissociation of select beta blockers: Acebutolol, atenolol, bisoprolol, carteolol, and labetalol
AbstractBeta blockers are a class of drugs commonly used to treat heart-related diseases; they are also regulated under the World Anti-Doping Agency. Tandem mass spectrometry is often used in the pharmaceutical industry, clinical analysis laboratory, and antidoping laboratory for detection and characterization of drugs and their metabolites. A deeper chemical understanding of dissociation pathways may eventually lead to an improved ability to predict tandem mass spectra of compounds based strictly on their chemical structure (or vice versa), which is especially important for characterization of unknowns such as emerging de...
Source: Journal of Mass Spectrometry - November 22, 2023 Category: Chemistry Authors: Matthew J. Carlo,
Amanda L. Patrick Tags: RESEARCH ARTICLE Source Type: research
Modelling some rod set imperfections of a quadrupole mass filter
AbstractThe problem of modeling the mass peak shape of a quadrupole mass filter (QMF) with round rods is considered. A number of factors leading to the degradation of the mass peak shape are studied, namely, displacement of the electrodes with respect to their original position, changes in the diameter of the electrodes, and asymmetry of the supply potentials. Decomposition of the rod set field on multipole fields allows to obtain an analytical representation of the ion motion equations. Simulations have shown that a parallel shift of one or two electrodes leads to a shift of the peak along the mass number axis and dips at...
Source: Journal of Mass Spectrometry - November 21, 2023 Category: Chemistry Authors: Pavel V. Bugrov,
Aleksey A. Sysoev,
Nikolai V. Konenkov Tags: RESEARCH ARTICLE Source Type: research
Fast saliva analysis by GC –MS with Cold EI and Open Probe Fast GC–MS with Cold EI for the detection of cannabis usage
AbstractSaliva is a body fluid that is much easier to collect and analyze than blood. Thus, saliva analysis for the detection of delta 9-tetrahydrocannabinol (delta 9-THC) can serve as a tool for law enforcement agents to detect cannabis consumption by drivers. Fast saliva analysis for the presence of delta 9-THC and/or cannabidiol (CBD) is described with both gas chromatography –mass spectrometry (GC–MS) with Cold electron ionization (EI) with good separation and in 10 min and/or with Open Probe Fast GC–MS with Cold EI in under 1 min full analysis cycle time. Saliva was taken directly from donors' tongues on a th...
Source: Journal of Mass Spectrometry - November 14, 2023 Category: Chemistry Authors: Oneg Elkabets,
Benny Neumark,
Aviv Amirav Tags: RESEARCH ARTICLE Source Type: research
Ionization behaviors of nitrotoluenes and dinitrotoluenes by reactions with acetone ‐related reactant ion
In this study, ionization behaviors of NT (2-, 3-, and 4-NTs) and DNT isomers (2,3-, 2,4-, and 2,6-DNTs) by reactions with [2Acetone + O2]•− were investigated. The energy-minimized structures of the product ions and their energies were calculated to explain the differences in the ionization behaviors. Typical NT- and DNT-related ions were produced by reactions with [2Acetone + O2]•−; NT•−, [NT – H]−, DNT•−, [DNT – H]−, and [DNT – NO]− ions. The ionization efficiencies of NT- and DNT-related ions increased by increasing the source fragmentor voltage, and those of DNT-related ions were h...
Source: Journal of Mass Spectrometry - November 11, 2023 Category: Chemistry Authors: He ‐Ryun Choi,
Sung‐Seen Choi Tags: RESEARCH ARTICLE Source Type: research
Simple and rapid quantification of ribociclib in rat plasma by protein precipitation and LC ‐MS/MS: An application to pharmacokinetics of ribociclib nanoparticles in rats
We present a fully validated, sensitive, and simple LC-MS/MS method for measuring ribociclib in rat plasma. Ribociclib-D6 was utilized as an internal standard, and a simple protein precipitation procedure with acetonitrile was used in sample preparation. Excellent assay linearity was observed over a standard curve concentration of 1.008 –1027.624 ng/mL. Acceptable intra- and inter-day accuracy and reproductivity were demonstrated for ribociclib quality controls (bias and CV% within ±15%). Complete extraction recovery of ribociclib was achieved, and a negligible matrix effect of analyte to internal standard ratio was o...
Source: Journal of Mass Spectrometry - November 11, 2023 Category: Chemistry Authors: Osama Y. Alshogran,
Ramadan Al ‐Shdefat,
Mohammad Hailat Tags: RESEARCH ARTICLE Source Type: research
Rapid classification and identification of chemical constituents in Leonurus japonicus Houtt based on UPLC ‐Q‐Orbitrap‐MS combined with data post‐processing techniques
In this study, ultra-performance liquid chromatography-quadrupole electrostatic field-orbital trap high resolution mass spectrometry (UPLC-Q-Orbitrap-MS) was successfully established, along with two data post-processing techniques, characteristic fragmentations (CFs) and neutral losses (NLs), to quickly classify and identify the chemical constituents in LJH. As a result, 44 constituents of LJH were identified, including four alkaloids, 20 flavonoids, two phenylpropanoids, 17 organic acids, and one amino acid. The method in this paper enables classification and identification of chemical compositions rapidly, providing a sc...
Source: Journal of Mass Spectrometry - November 10, 2023 Category: Chemistry Authors: Yajie Dou,
Lexin Shu,
Xuchen Jia,
Yaqi Yao,
Siyue Chen,
Yanyan Xu,
Yubo Li Tags: RESEARCH ARTICLE Source Type: research
Correction to “Exploration of chiral drugs as references for chiral discrimination of valsartan and voriconazole by tandem mass spectrometry”
(Source: Journal of Mass Spectrometry)
Source: Journal of Mass Spectrometry - November 10, 2023 Category: Chemistry Tags: CORRECTION Source Type: research
Interactions of CyMe4 ‐BTBP ligand with lanthanides and actinides: Insights from ESI‐MS and DFT calculations
AbstractElectrospray Ionization Mass Spectrometry (ESI-MS) technique and density functional theory (DFT) calculations were combined to study the formation of the complexes of lanthanides (Ln = La, Ce, Nd, Sm, Eu, Yb) and actinides (UO22+, Th4+) with CyMe4-BTBP (6,6 ′-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-benzo-[1,2,4-]triazin-3-yl)-[2,2′]bipyridine) to understand the mechanisms during the extraction process. Mass spectrometry titrations showed the formation of the complexation in acetonitrile. For lanthanides, only 1:2 complexes ([Ln(L)2]3+, [Ln(L)2(CH3CN)]3+), [Ln(L)2(NO3)]2+) were found at low [Ln]/[L] conc...
Source: Journal of Mass Spectrometry - October 31, 2023 Category: Chemistry Authors: Qi ‐Qi Zhang,
Yang Liu,
Shu‐Ping Tan,
Yan Chen,
Jie Gao,
Xin‐Yue Liang,
Wei‐Qun Shi,
Yong‐Gang Zhao Tags: RESEARCH ARTICLE Source Type: research
