Structure, anion, and solvent effects on cation response in ESI-MS

2019 ◽  
Author(s):  
Isaac Omari ◽  
Parmissa Randhawa ◽  
Jaiya Randhawa ◽  
Jenny Yu ◽  
J Scott McIndoe
Keyword(s):  
Predictive Power ◽  
Solution Concentration ◽  
High Reactivity ◽  
Chemical Processes ◽  
Ionization Mass ◽  
Solution Composition ◽  
Ionization Mass Spectrum ◽  
Electrospray Ionization Mass Spectrum ◽  
Cation Response ◽  
Insight Into

<p>The abundance of an ion in an electrospray ionization mass spectrum is dependent on many factors beyond just solution concentration. Even in cases where the ions are permanently charged and do not rely on protonation or other chemical processes to acquire the necessary charge, factors such as cation structure, molecular weight, solvent, and the identity of the anion can perturb results. Screening of a variety of combinations of cation, anion and solvent provided insight into some of the more important factors. Rigid cations and high conductivity anions tended to provide the highest responses, while acetonitrile was the most accurate solvent for reflecting solution composition. Functional groups that had affinity for the solvent tended to depress response. These observations will provide predictive power when accounting for ions that for reasons of high reactivity can not be isolated.</p><br>

Structure, anion, and solvent effects on cation response in ESI-MS

2019 ◽  
Author(s):  
Isaac Omari ◽  
Parmissa Randhawa ◽  
Jaiya Randhawa ◽  
Jenny Yu ◽  
J Scott McIndoe
Keyword(s):  
Predictive Power ◽  
Solution Concentration ◽  
High Reactivity ◽  
Chemical Processes ◽  
Ionization Mass ◽  
Solution Composition ◽  
Ionization Mass Spectrum ◽  
Electrospray Ionization Mass Spectrum ◽  
Cation Response ◽  
Insight Into

<p>The abundance of an ion in an electrospray ionization mass spectrum is dependent on many factors beyond just solution concentration. Even in cases where the ions are permanently charged and do not rely on protonation or other chemical processes to acquire the necessary charge, factors such as cation structure, molecular weight, solvent, and the identity of the anion can perturb results. Screening of a variety of combinations of cation, anion and solvent provided insight into some of the more important factors. Rigid cations and high conductivity anions tended to provide the highest responses, while acetonitrile was the most accurate solvent for reflecting solution composition. Functional groups that had affinity for the solvent tended to depress response. These observations will provide predictive power when accounting for ions that for reasons of high reactivity can not be isolated.</p><br>

Oxidative Desulfurization of Dibenzothiophene Catalyzed by Polyoxometalate-Based Ionic Liquid

2014 ◽  
Vol 1033-1034 ◽  
pp. 65-69
Author(s):  
Min Wang ◽  
Qin Wu ◽  
Han Sheng Li ◽  
Yun Zhao ◽  
Qing Ze Jiao
Keyword(s):  
Ionic Liquid ◽  
Sulfonic Acid ◽  
Sulfur Removal ◽  
Oxidative Desulfurization ◽  
Ionization Mass ◽  
Thermogravimetric Analyzer ◽  
Catalytic Oxidative Desulfurization ◽  
Ionization Mass Spectrum ◽  
Electrospray Ionization Mass Spectrum ◽  
Desulfurization Process

A polyoxometalate-based ionic liquid, 1-(4-sulfonic acid) methylimidazolium phosphotungstate ([MIMBS]3PW12O40), was synthesized and characterized by Fourier transform infrared spectrum, nuclear magnetic resonance, electrospray ionization mass spectrum and thermogravimetric analyzer. [MIMBS]3PW12O40exhibited high activity for the extractive catalytic oxidative desulfurization process, together with H2O2and CH3CN/H2O. The sulfur removal of DBT could reach 99.9% under wild conditions, and the catalyst could be used three times with only a slight decline in activity.

scholarly journals Soot and charcoal are reservoirs of extracellular DNA

2021 ◽  
Author(s):  
Stanislav Jelavic ◽  
Lisbeth Garbrecht Thygesen ◽  
Valerie Magnin ◽  
Nathaniel Findling ◽  
Sascha Müller ◽  
...  
Keyword(s):  
Hydrophobic Interactions ◽  
Antibiotic Resistance Genes ◽  
Solution Concentration ◽  
Low Ph ◽  
Extracellular Dna ◽  
Biological Degradation ◽  
Environmental Matrices ◽  
Solution Composition ◽  
Dna Adsorption ◽  
Insight Into

Soot and charcoal are carbonaceous materials widespread in the environment where they readily can come in contact with extracellular DNA shed from organisms. The adsorption at a surface protects DNA from chemical and biological degradation. However, a comprehensive insight into DNA adsorption at soot and charcoal is lacking. We measured DNA adsorption capacity at soot and charcoal as a function of solution composition, time and DNA length. We observed that the capacity for DNA is the highest at low pH, it increases with solution concentration and cation valency and that the activation energy for DNA adsorption at both soot and charcoal is ~50 kJmol-1. We demonstrate how the interaction between DNA and soot and charcoal partly occurs via terminal basepairs, suggesting that, besides electrostatic forces, hydrophobic interactions play an important role in binding. The importance of hydrophobic interactions increases as the hydrophobicity of a surface increases. Such strong binding and hydrophobic interactions need to be taken into account to improve DNA extraction protocols and for mitigation of the spread of antibiotic resistance genes in environmental matrices that contain soot and charcoal such as aerosol, wastewater and topsoil.

Role of sterics in phosphine-ligated gold clusters

2019 ◽  
Vol 21 (4) ◽  
pp. 1689-1699 ◽  
Author(s):  
Katherine A. Parrish ◽  
Mary King ◽  
Marshall R. Ligare ◽  
Grant E. Johnson ◽  
Heriberto Hernández
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Ionization ◽  
Ligand Exchange ◽  
Gold Clusters ◽  
Solution Phase ◽  
Ionization Mass ◽  
Exchange Reactions ◽  
The Stability ◽  
Insight Into

This study examined the solution-phase exchange reactions of triphenylphosphine (PPh3) ligands on Au8L72+ (L = PPh3) gold clusters with three different tolyl ligands using electrospray ionization mass spectrometry to provide insight into how steric differences in the phosphines influence the extent of ligand exchange and the stability of the resulting mixed-phosphine clusters.

Nonsuicidal Self-Injury and Its Relation to Suicidal Behavior

2014 ◽  
Author(s):  
Joseph C. Franklin ◽  
Matthew K. Nock
Keyword(s):  
Suicidal Behavior ◽  
Predictive Power ◽  
Suicide Attempts ◽  
Strong Association ◽  
Future Directions ◽  
Suicidal Intent ◽  
Self Injury ◽  
Basic Features ◽  
Insight Into ◽  
Nonsuicidal Self Injury

Nonsuicidal self-injury (NSSI) is the direct and intentional destruction of one’s own body tissue in the absence of suicidal intent. Although NSSI itself is explicitly nonsuicidal, nearly half of individuals who engage in NSSI also engage in suicidal behavior, and nearly all individuals who engage in suicidal behavior also engage in NSSI. Moreover, recent studies suggest that NSSI is one of the strongest known predictors of future suicide attempts, even exceeding the predictive power of prior suicide attempts in some instances. In this chapter we review the basic features and correlates of NSSI, evaluate the evidence for traditional models of NSSI, and discuss how an emerging model of NSSI may provide insight into the strong association between NSSI and suicidal behavior. We conclude by recommending how to evaluate when NSSI is a behavioral emergency and by noting the most crucial future directions for research on this topic.

scholarly journals Chemical and physical origins of friction on surfaces with atomic steps

2019 ◽  
Vol 5 (8) ◽  
pp. eaaw0513 ◽  
Author(s):  
Zhe Chen ◽  
Arash Khajeh ◽  
Ashlie Martini ◽  
Seong H. Kim
Keyword(s):  
Friction Coefficient ◽  
Relative Motion ◽  
Single Layer ◽  
Chemical Processes ◽  
Single Layer Graphene ◽  
Atomic Steps ◽  
Layer Graphene ◽  
Lateral Forces ◽  
Physical And Chemical ◽  
Insight Into

Friction occurs through a complex set of processes that act together to resist relative motion. However, despite this complexity, friction is typically described using a simple phenomenological expression that relates normal and lateral forces via a coefficient, the friction coefficient. This one parameter encompasses multiple, sometimes competing, effects. To better understand the origins of friction, here, we study a chemically and topographically well-defined interface between silica and graphite with a single-layer graphene step edge. We identify the separate contributions of physical and chemical processes to friction and show that a single friction coefficient can be separated into two terms corresponding to these effects. The findings provide insight into the chemical and topographic origins of friction and suggest means of tuning surfaces by leveraging competing frictional processes.

scholarly journals Temperature-controlled electrospray ionization mass spectrometry as a tool to study collagen homo- and heterotrimers

2019 ◽  
Vol 10 (42) ◽  
pp. 9829-9835 ◽  
Author(s):  
Martin Köhler ◽  
Adrien Marchand ◽  
Nina B. Hentzen ◽  
Jasmine Egli ◽  
Alina I. Begley ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Ionization ◽  
Electrospray Ionization Mass Spectrometry ◽  
Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Triple Helices ◽  
Temperature Controlled ◽  
Temperature Programmed ◽  
Insight Into

Temperature-programmed native electrospray ionization mass spectrometry gives detailed insight into the assembly of model collagen triple helices.

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