scholarly journals Highly sensitive 26Al measurements by Ion-Laser-InterAction Mass Spectrometry

2021 ◽  
Vol 465 ◽  
pp. 116576
Author(s):  
Johannes Lachner ◽  
Martin Martschini ◽  
Andreas Kalb ◽  
Michael Kern ◽  
Oscar Marchhart ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Laser Interaction ◽  
Highly Sensitive ◽  
Ion Laser

scholarly journals 5 YEARS OF ION-LASER INTERACTION MASS SPECTROMETRY—STATUS AND PROSPECTS OF ISOBAR SUPPRESSION IN AMS BY LASERS

Radiocarbon ◽  
2021 ◽  
pp. 1-14
Author(s):  
Martin Martschini ◽  
Johannes Lachner ◽  
Karin Hain ◽  
Michael Kern ◽  
Oscar Marchhart ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Reproducibility Of Results ◽  
Beam Energy ◽  
State Of The Art ◽  
Ion Beam ◽  
Laser Interaction ◽  
Molecular Dissociation ◽  
Additional Element ◽  
Ion Laser ◽  
Reliability And Robustness

ABSTRACT A setup for ion-laser interaction was coupled to the state-of-the-art AMS facility VERA five years ago and its potential and applicability as a new means of isobar suppression in accelerator mass spectrometry (AMS) has since been explored. Laser photodetachment and molecular dissociation processes of anions provide unprecedented isobar suppression factors of >1010 for several established AMS isotopes like 36Cl or 26Al and give access to new AMS isotopes like 90Sr, 135Cs or 182Hf at a 3-MV-tandem facility. Furthermore, Ion-Laser InterAction Mass Spectrometry has been proven to meet AMS requirements regarding reliability and robustness with a typical reproducibility of results of 3%. The benefits of the technique are in principle available to any AMS machine, irrespective of attainable ion beam energy. Since isobar suppression via this technique is so efficient, there often is no need for any additional element separation in the detection setup and selected nuclides may even become accessible without accelerator at all.

A Novel Simultaneous Estimation of Sofosbuvir and Velpatasvir in Human Plasma by Liquid Chromatography Tandem-Mass Spectrometry after Protein Precipitation Method

2019 ◽  
Vol 15 (7) ◽  
pp. 710-715
Author(s):  
S.T. Narenderan ◽  
Basuvan Babu ◽  
T. Gokul ◽  
Subramania Nainar Meyyanathan
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Human Plasma ◽  
Multiple Reaction Monitoring ◽  
Simultaneous Estimation ◽  
Pharmacokinetic Studies ◽  
Tandem Mass ◽  
Mass Spectrometric Method ◽  
Highly Sensitive ◽  
Tandem Mass Spectrometric

Objective: The aim of the present work is to achieve a novel highly sensitive chromatographic method for the simultaneous determination of hepatitis C agents, sofosbuvir and velpatasvir from human plasma using ritonavir as an internal standard. Methods: Chromatographic separation was achieved using Hypersil C18 column (50mm x 4.6mm, 3μm) with an isocratic elution mode using the mobile phase composition 10 mM ammonium formate buffer (pH 5.0): acetonitrile (20:80 v/v) pumped at a flow rate of 0.5 ml/min. The detection was carried out by tandem mass spectrometry using Multiple Reaction Monitoring (MRM) positive Electrospray Ionization (ESI) with proton adducts at m/z 530.10 > 243.10, 883.40 > 114.0 and 721.25 > 197.0. Results: The method validated as per USFDA guidelines with respect to linearity, accuracy, and precision was found to be acceptable over the concentration range of 0.2–2000 ng/ml and 5-2000 ng/ml for sofosbuvir and velpatasvir respectively and the method was found to be highly sensitive and selective. Conclusion: The developed tandem mass spectrometric method is robust and can be applied for the monitoring of plasma levels of the analyzed drug in preclinical and clinical pharmacokinetic studies.

scholarly journals Neurodegenerative Proteinopathies in the Proteoform Spectrum—Tools and Challenges

2021 ◽  
Vol 22 (3) ◽  
pp. 1085
Author(s):  
Aneeqa Noor ◽  
Saima Zafar ◽  
Inga Zerr
Keyword(s):  
Mass Spectrometry ◽  
Neurodegenerative Disorders ◽  
Gel Electrophoresis ◽  
Large Fraction ◽  
Imaging Mass Spectrometry ◽  
Living Tissue ◽  
Disease Prognosis ◽  
Highly Sensitive ◽  
Jakob Disease ◽  
Hydrophobic Nature

Proteinopathy refers to a group of disorders defined by depositions of amyloids within living tissue. Neurodegenerative proteinopathies, including Alzheimer’s disease, Parkinson’s disease, Creutzfeldt–Jakob disease, and others, constitute a large fraction of these disorders. Amyloids are highly insoluble, ordered, stable, beta-sheet rich proteins. The emerging theory about the pathophysiology of neurodegenerative proteinopathies suggests that the primary amyloid-forming proteins, also known as the prion-like proteins, may exist as multiple proteoforms that contribute differentially towards the disease prognosis. It is therefore necessary to resolve these disorders on the level of proteoforms rather than the proteome. The transient and hydrophobic nature of amyloid-forming proteins and the minor post-translational alterations that lead to the formation of proteoforms require the use of highly sensitive and specialized techniques. Several conventional techniques, like gel electrophoresis and conventional mass spectrometry, have been modified to accommodate the proteoform theory and prion-like proteins. Several new ones, like imaging mass spectrometry, have also emerged. This review aims to discuss the proteoform theory of neurodegenerative disorders along with the utility of these proteomic techniques for the study of highly insoluble proteins and their associated proteoforms.

scholarly journals Mass Spectrometry versus Conventional Techniques of Protein Detection: Zika Virus NS3 Protease Activity towards Cellular Proteins

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3732
Author(s):  
Agnieszka Dabrowska ◽  
Aleksandra Milewska ◽  
Joanna Ner-Kluza ◽  
Piotr Suder ◽  
Krzysztof Pyrc
Keyword(s):  
Mass Spectrometry ◽  
Zika Virus ◽  
Viral Infections ◽  
Protein Detection ◽  
Extensive Discussion ◽  
Protein Targets ◽  
Highly Sensitive ◽  
Infected Cells ◽  
Ns3 Protease ◽  
To Receive

Mass spectrometry (MS) used in proteomic approaches is able to detect hundreds of proteins in a single assay. Although undeniable high analytical power of MS, data acquired sometimes lead to confusing results, especially during a search of very selective, unique interactions in complex biological matrices. Here, we would like to show an example of such confusing data, providing an extensive discussion on the observed phenomenon. Our investigations focus on the interaction between the Zika virus NS3 protease, which is essential for virus replication. This enzyme is known for helping to remodel the microenvironment of the infected cells. Several reports show that this protease can process cellular substrates and thereby modify cellular pathways that are important for the virus. Herein, we explored some of the targets of NS3, clearly shown by proteomic techniques, as processed during infection. Unfortunately, we could not confirm the biological relevance of protein targets for viral infections detected by MS. Thus, although mass spectrometry is highly sensitive and useful in many instances, also being able to show directions where cell/virus interaction occurs, we believe that deep recognition of their biological role is essential to receive complete insight into the investigated process.

TESTOSTERONE AND DIHYDROTESTOSTERONE CONCENTRATIONS IN THE FLUID MILIEU OF SPERMATOZOA IN THE REPRODUCTIVE TRACT OF THE BULL

1973 ◽  
Vol 74 (1) ◽  
pp. 186-200 ◽  
Author(s):  
Venkataseshu K. Ganjam ◽  
Rupert P. Amann
Keyword(s):  
Mass Spectrometry ◽  
Seminal Plasma ◽  
Reproductive Tract ◽  
Binding Assay ◽  
Rete Testis ◽  
Protein Binding Assay ◽  
Highly Sensitive ◽  
Competitive Protein Binding Assay ◽  
Competitive Protein Binding ◽  
Isolated Compound

ABSTRACT Total 17β-hydroxyandrogen concentrations were determined using a competitive protein binding assay, for bovine reproductive fluids. Rete testis fluid and cauda epididymal plasma were separated from the spermcontaining fluids obtained through cannulae from conscious bulls. Al-through the concentration of total 17β-hydroxyandrogens in rete testis fluid was similar (P > 0.05) to that in cauda epididymal plasma (25 and 19 ng/ml), both fluids contained higher (P < 0.01) androgen concentrations than seminal plasma, accessory sex gland fluid or serum from peripheral blood (3–5 ng/ml). However, since the amount of cauda epididymal plasma recovered was much less than for rete testis fluid (0.25 vs 35 ml/day), cauda epididymal plasma contained less than 1 % of the total 17β-hydroxyandrogens which entered the epididymis in rete testis fluid (5 vs 883 ng/day). Testosterone and/or dihydrotestosterone were isolated from the reproductive fluids by Sephadex LH-20 chromatography and quantified by a simple, specific and highly sensitive microassay. Dihydrotestosterone was found only in cauda epididymal plasma (14 ng/ml); identification of the isolated compound was confirmed by mass spectrometry. Dihydrotestosterone accounted for 52% of the 17β-hydroxyandrogens in cauda epididymal plasma while 23 % was testosterone. Testosterone represented 70 % of the 17β-hydroxyandrogens in rete testis fluid and 91 % of those in blood serum. Physiological implications of this shift in androgen balance are discussed.

scholarly journals Hyphenated Mass Spectrometry versus Real-Time Mass Spectrometry Techniques for the Detection of Volatile Compounds from the Human Body

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7185
Author(s):  
Oliver Gould ◽  
Natalia Drabińska ◽  
Norman Ratcliffe ◽  
Ben de Lacy Costello
Keyword(s):  
Mass Spectrometry ◽  
Volatile Compounds ◽  
Real Time ◽  
Qualitative Data ◽  
Method Development ◽  
Complex Matrices ◽  
Analytical Technique ◽  
Monitoring Drug ◽  
Highly Sensitive ◽  
Insight Into

Mass spectrometry (MS) is an analytical technique that can be used for various applications in a number of scientific areas including environmental, security, forensic science, space exploration, agri-food, and numerous others. MS is also continuing to offer new insights into the proteomic and metabolomic fields. MS techniques are frequently used for the analysis of volatile compounds (VCs). The detection of VCs from human samples has the potential to aid in the diagnosis of diseases, in monitoring drug metabolites, and in providing insight into metabolic processes. The broad usage of MS has resulted in numerous variations of the technique being developed over the years, which can be divided into hyphenated and real-time MS techniques. Hyphenated chromatographic techniques coupled with MS offer unparalleled qualitative analysis and high accuracy and sensitivity, even when analysing complex matrices (breath, urine, stool, etc.). However, these benefits are traded for a significantly longer analysis time and a greater need for sample preparation and method development. On the other hand, real-time MS techniques offer highly sensitive quantitative data. Additionally, real-time techniques can provide results in a matter of minutes or even seconds, without altering the sample in any way. However, real-time MS can only offer tentative qualitative data and suffers from molecular weight overlap in complex matrices. This review compares hyphenated and real-time MS methods and provides examples of applications for each technique for the detection of VCs from humans.

Sign in / Sign up

Export Citation Format

Share Document