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.

Effects of ion source parameters on ion beam energy in mass spectrometry

1990 ◽  
Vol 62 (14) ◽  
pp. 1547-1549 ◽  
Author(s):  
Kuangnan. Qian ◽  
Anil. Shukla ◽  
Jean. Futrell
Keyword(s):  
Mass Spectrometry ◽  
Beam Energy ◽  
Ion Beam ◽  
Source Parameters ◽  
Ion Source

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 Characterization and Quantification of Selenoprotein P: Challenges to Mass Spectrometry

2021 ◽  
Vol 22 (12) ◽  
pp. 6283
Author(s):  
Jérémy Lamarche ◽  
Luisa Ronga ◽  
Joanna Szpunar ◽  
Ryszard Lobinski
Keyword(s):  
Mass Spectrometry ◽  
State Of The Art ◽  
Animal Health ◽  
Primary Standard ◽  
Selenoprotein P ◽  
Primary Standards ◽  
Analytical Approaches ◽  
Careful Investigation ◽  
Accurate Quantification

Selenoprotein P (SELENOP) is an emerging marker of the nutritional status of selenium and of various diseases, however, its chemical characteristics still need to be investigated and methods for its accurate quantitation improved. SELENOP is unique among selenoproteins, as it contains multiple genetically encoded SeCys residues, whereas all the other characterized selenoproteins contain just one. SELENOP occurs in the form of multiple isoforms, truncated species and post-translationally modified variants which are relatively poorly characterized. The accurate quantification of SELENOP is contingent on the availability of specific primary standards and reference methods. Before recombinant SELENOP becomes available to be used as a primary standard, careful investigation of the characteristics of the SELENOP measured by electrospray MS and strict control of the recoveries at the various steps of the analytical procedures are strongly recommended. This review critically discusses the state-of-the-art of analytical approaches to the characterization and quantification of SELENOP. While immunoassays remain the standard for the determination of human and animal health status, because of their speed and simplicity, mass spectrometry techniques offer many attractive and complementary features that are highlighted and critically evaluated.

scholarly journals State-of-the-Art Native Mass Spectrometry and Ion Mobility Methods to Monitor Homogeneous Site-Specific Antibody-Drug Conjugates Synthesis

2021 ◽  
Vol 14 (6) ◽  
pp. 498
Author(s):  
Evolène Deslignière ◽  
Anthony Ehkirch ◽  
Bastiaan L. Duivelshof ◽  
Hanna Toftevall ◽  
Jonathan Sjögren ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Phase ◽  
Ion Mobility ◽  
State Of The Art ◽  
Native Mass Spectrometry ◽  
Site Specific ◽  
Drug Conjugates ◽  
Conjugation Process ◽  
Antibody Drug

Antibody-drug conjugates (ADCs) are biotherapeutics consisting of a tumor-targeting monoclonal antibody (mAb) linked covalently to a cytotoxic drug. Early generation ADCs were predominantly obtained through non-selective conjugation methods based on lysine and cysteine residues, resulting in heterogeneous populations with varying drug-to-antibody ratios (DAR). Site-specific conjugation is one of the current challenges in ADC development, allowing for controlled conjugation and production of homogeneous ADCs. We report here the characterization of a site-specific DAR2 ADC generated with the GlyCLICK three-step process, which involves glycan-based enzymatic remodeling and click chemistry, using state-of-the-art native mass spectrometry (nMS) methods. The conjugation process was monitored with size exclusion chromatography coupled to nMS (SEC-nMS), which offered a straightforward identification and quantification of all reaction products, providing a direct snapshot of the ADC homogeneity. Benefits of SEC-nMS were further demonstrated for forced degradation studies, for which fragments generated upon thermal stress were clearly identified, with no deconjugation of the drug linker observed for the T-GlyGLICK-DM1 ADC. Lastly, innovative ion mobility-based collision-induced unfolding (CIU) approaches were used to assess the gas-phase behavior of compounds along the conjugation process, highlighting an increased resistance of the mAb against gas-phase unfolding upon drug conjugation. Altogether, these state-of-the-art nMS methods represent innovative approaches to investigate drug loading and distribution of last generation ADCs, their evolution during the bioconjugation process and their impact on gas-phase stabilities. We envision nMS and CIU methods to improve the conformational characterization of next generation-empowered mAb-derived products such as engineered nanobodies, bispecific ADCs or immunocytokines.

Time resolved diagnostic of ion beam energy distribution function for plasma thrusters

1997 ◽  
Author(s):  
Christelle Philippe ◽  
Claude Laure ◽  
Andre Bouchoule ◽  
Christelle Philippe ◽  
Claude Laure ◽  
...  
Keyword(s):  
Distribution Function ◽  
Energy Distribution ◽  
Beam Energy ◽  
Ion Beam ◽  
Energy Distribution Function ◽  
Time Resolved ◽  
Plasma Thrusters
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