A massive advance in spectrometry
Study results may lead to more accurate medical, biological, and chemical tests
mass spectrometers (MS) have become essential tools in chemistry and biology laboratories. The ability to quickly identify the chemical components in a sample allows them to take part in a diverse array of experiments, including radiocarbon dating, protein analysis, and monitoring drug metabolism.
A depiction of charge reduction process which is utilized as a pre-treatment process of mass spectrometry, MS (or ion mobility spectrometry, IMS). To increase the accuracy of spectrum, excess charges on the molecular ion (PEG in this figure) is removed via collision with anion in gas.
Kanazawa University
An outline of developed calculation model (continuum - molecular dynamics simulation hybrid method). In this model, when inter-ion distance is sufficiently far, relative motion is described by diffusion equations (continuum), meanwhile within a specific distance (written in broken line), molecular dynamics (MD) simulations are utilized to calculate the trajectory. In order to increase calculation cost. we perform MD simulation with arranging gas molecules only around target ions.
Kanazawa University
(a) The recombination (collision) rate coefficient of PEG ion with different number of charges. This collision rate coefficient showed good agreement with experimentally measured charge reduction rate. (b) Translational velocity distribution of NO2- ion at collision. We expect the kinetic energy can be used to evaluate the possibility of collision induced reaction.
Kanazawa University
MS instruments work by giving the analyte molecules an electric charge, and shooting them through a region of space with a uniform electric field, which curves their trajectory into a circle. The radius of the circle, which depends on the ratio of the molecule's mass to its charge, is detected and compared with known samples. Because the method can only measure this ratio, not the mass itself, excess charges can lead to inaccurate or ambiguous results.
Now, a team of researchers lead by Kanazawa University used a powerful molecular dynamics simulation to better understand the effect of excess charges on molecules tested by a MS. They modeled the effect of adding molecules of the opposite charge in order to neutralize excess charge. In this case, the positive charge on polyethylene glycol (PEG) can be reduced via collision with negatively charged NO2- ions.
However, this is complicated by the fact that the likelihood of colliding depends on the amount of charge in the first place. "Charged polymers can adopt charge-state dependent structures because of electrostatic stretching," first author Tomoya Tamadate says. For example, with small excess charge, PEG assumes a compact form. However, as the charge increased, the mutual repulsion between the positive charges causes it to straighten out.
To help speed up the calculations, the team used the "continuum approximation" method, which only started simulating all of the atoms in the NO2- molecule once it approached close enough to the PEG.
"The success of this project shows that hybrid continuum-molecular dynamics simulations can be used more generally to study collision-driven reactions molecules that can take on different conformations," senior author Takafumi Seto says. The results can lead to more effective methods of controlling excess charge in sample molecules, which will allow for more accurate results.
Original publication
Other news from the department science
These products might interest you
isoprime precisION by Elementar Analysensysteme
isoprime precisION stable isotope ratio mass spectrometer
The most flexible, yet powerful isotope ratio mass spectrometer ever created
PlasmaQuant MS Elite by Analytik Jena
LC-ICP-MS Is the Key to the World of Elemental Species
Highest Sensitivity and Lowest Detection Limits with PlasmaQuant MS Series and PQ LC
HPR-20 OEMS, Online Electrochemical Mass Spectrometer by Hiden Analytical
Online monitoring and quantification of evolved gases and vapours from electrochemical processes
A complete gas analysis solution, designed to integrate seamlessly with electrochemical applications
IonTamer ToF MS by Spacetek Technology
IonTamer instruments are time-of-flight residual gas analysers (TOF-RGA) for the analysis of gases
Compact Time-of-flight residual gas analyzer (TOF-RGA) for process analysis
Xevo TQ Absolute by Waters
A new Tandem Quadrupole Mass Spectrometer for Quantification with Absolute power
Absolute performance, efficiency, productivity, and confidence for your most challenging compounds
BIOS ANALYTIQUE - Soluciones de Renting y Leasing para laboratorios by Bios Analytique
Specialists in the rental and leasing of scientific equipment for laboratories throughout Europe
Whether you have an unexpected requirement or limited budget, we have the perfect solution for you
HPR-20 R&D by Hiden Analytical
A specialist benchtop triple filter mass spectrometer for the monitoring of evolved gases & vapours
Providing improved resolution & abundance sensitivity with an ultimate detection limit of 5 ppb sub
CATLAB Catalysis and Thermal Analysis by Hiden Analytical
A system for catalyst characterisation, kinetic and thermodynamic measurements
Integrated Microreactor-Mass Spectrometer for Reaction Testing, TPD/R/O and Pulse Chemisorption.
NexION® 5000 by PerkinElmer
NexION 5000 Multi-Quadrupole ICP Mass Spectrometer
NexION 5000 Multi-Quadrupole ICP Mass Spectrometer
iCAP TQ Triple Quadrupole ICP-MS by Thermo Fisher Scientific
Overcome unexpected interferences, reduce detection limits and improve data quality
Ultralow limits of detection with simplicity - even for the most challenging analytical applications
iCAP RQ single Quadrupole ICP-MS by Thermo Fisher Scientific
Robust ICP-MS with ease of use and high productivity for routine analysis
A complete multi-element analysis solution for your high-throughput routine laboratory
JEOL JMS-T2000GC AccuTOF GC-Alpha Time-of-Flight Mass Spectrometer by JEOL
A new era of mass spectrometry for your fast forward daily lab routine:
Welcome JEOL AccuTOF GC-Alpha
Stop wrong hypotheses and uneconomic loops! Precise data without compromise is now.
Thermo Scientific TSQ Triple Quadrupole Mass Spectrometry Systems by Thermo Fisher Scientific
Confident quantitation with triple quadrupole LC-MS systems
Mass Spectrometry Systems
Orbitrap Exploris GC Mass Spectrometer by Thermo Fisher Scientific
Orbitrap Exploris GC-MS simplifies operations and offers new opportunities for analytical testing
Keep pace with changing demands, maximize system uptime, and expand laboratory capability.
expression® Compact Mass Spectrometer by Advion Interchim Scientific
Mass Spectrometry for Chemists: Fast, Easy, Prep-Free Reaction Monitoring at the Bench
Featuring a variety of sample introduction techniques that also allow TLC/MS & direct probe analysis
TSQ 9610 GC-MS/MS by Thermo Fisher Scientific
TSQ 9610 GC-MS/MS for superb sensitivity and selectivity with outstanding reliable productivity
Eliminate unnecessary, unplanned instrument downtime, save helium and maximize productivity
Get the chemical industry in your inbox
From now on, don't miss a thing: Our newsletter for the chemical industry, analytics, lab technology and process engineering brings you up to date every Tuesday and Thursday. The latest industry news, product highlights and innovations - compact and easy to understand in your inbox. Researched by us so you don't have to.
See the theme worlds for related content
Topic World Spectroscopy
Investigation with spectroscopy gives us unique insights into the composition and structure of materials. From UV-Vis spectroscopy to infrared and Raman spectroscopy to fluorescence and atomic absorption spectroscopy, spectroscopy offers us a wide range of analytical techniques to precisely characterize substances. Immerse yourself in the fascinating world of spectroscopy!
Topic World Spectroscopy
Investigation with spectroscopy gives us unique insights into the composition and structure of materials. From UV-Vis spectroscopy to infrared and Raman spectroscopy to fluorescence and atomic absorption spectroscopy, spectroscopy offers us a wide range of analytical techniques to precisely characterize substances. Immerse yourself in the fascinating world of spectroscopy!
Topic World Mass Spectrometry
Mass spectrometry enables us to detect and identify molecules and reveal their structure. Whether in chemistry, biochemistry or forensics - mass spectrometry opens up unexpected insights into the composition of our world. Immerse yourself in the fascinating world of mass spectrometry!
Topic World Mass Spectrometry
Mass spectrometry enables us to detect and identify molecules and reveal their structure. Whether in chemistry, biochemistry or forensics - mass spectrometry opens up unexpected insights into the composition of our world. Immerse yourself in the fascinating world of mass spectrometry!
