A Mass Spectrometer's Building Blocks

Westman‐Brinkmalm, Ann; Brinkmalm, Gunnar

doi:10.1002/9780470395813.ch2

Cited by 8 publications

(3 citation statements)

References 270 publications

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“…In brief, in an ion-trap mass spectrometer, packets of ions with a range of m/z ratios are introduced, trapped and stored in a potential well. By varying the potentials of this potential well, ions with different m/z ratios are then sequentially ejected from the well (the trap) and detected [118]. Several ion trap mass spectrometers including a miniature toroidal mass analyzer, as well as commercial units from Torion Technologies (model Guardion) and Thermo Fisher Scientific (model ITQ), are mentioned [96,117].…”

Section: Molecular Mass Spectrometry With Portable/fieldable Mass Spectrometermentioning

confidence: 99%

Scoping study to expedite development of a field deployable and portable instrument for UF6 enrichment assay

Chan¹,

Valentine²,

Russo³

2017

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The primary objective of the present study is to identity the most promising, viable technologies that are likely to culminate in an expedited development of the next-generation, field-deployable instrument for providing rapid, accurate, and precise enrichment assay of uranium hexafluoride (UF 6 ). UF 6 is typically involved, and is arguably the most important uranium compound, in uranium enrichment processes. As the first line of defense against proliferation, accurate analytical techniques to determine the uranium isotopic distribution in UF 6 are critical for materials verification, accounting, and safeguards at enrichment plants. As nuclear fuel cycle technology becomes more prevalent around the world, international nuclear safeguards and interest in UF 6 enrichment assay has been growing.At present, laboratory-based mass spectrometry (MS), which offers the highest attainable analytical accuracy and precision, is the technique of choice for the analysis of stable and longlived isotopes. Currently, the International Atomic Energy Agency (IAEA) monitors the production of enriched UF 6 at declared facilities by collecting a small amount (between 1 to 10 g) of gaseous UF 6 into a sample bottle, which is then shipped under chain of custody to a central laboratory (IAEA's Nuclear Materials Analysis Laboratory) for high-precision isotopic assay by MS. The logistics are cumbersome and new shipping regulations are making it more difficult to transport UF 6 . Furthermore, the analysis is costly, and results are not available for some time after sample collection. Hence, the IAEA is challenged to develop effective safeguards approaches at enrichment plants. In-field isotopic analysis of UF 6 has the potential to substantially reduce the time, logistics and expense of sample handling. However, current laboratory-based MS techniques require too much infrastructure and operator expertise for field deployment and operation. As outlined in the IAEA Department of Safeguards Long-Term R&D Plan, 2012-2023, one of the IAEA long-term R&D needs is to "develop tools and techniques to enable timely, potentially real-time, detection of HEU (Highly Enriched Uranium) production in LEU (Lowly Enriched Uranium) enrichment facilities" (Milestone 5.2). iv measurements that do not require the stated high accuracy or precision of the ITVs to which it was compared).The list presented below summarizes the outcome of the present study, and groups all reviewed techniques into "recommended", "promising", or "not recommended"; the "benchmark" techniques are also included and labeled as such. The list is presented in a highly abridged way such that only the final recommendations are given. The performance of a technique in the seven evaluation metrics and its ranking are summarized in Table 6.1, whereas short discussion and comments on the recommendation can be found in Section 6.2 of this report. Furthermore, comprehensive and in-depth reviews on the scientific principle of each technique, its instrument option, its limitations and main gaps betwe...

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Section: Molecular Mass Spectrometry With Portable/fieldable Mass Spectrometermentioning

confidence: 99%

Scoping study to expedite development of a field deployable and portable instrument for UF6 enrichment assay

Chan¹,

Valentine²,

Russo³

2017

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“…Although VOCs can be collectively detected by various gas sensors and detectors, these devices typically lack the selectivity to discriminate between constituents of complex mixtures. Simple gas compounds can be analyzed by high-performance mass spectrometry and infrared spectroscopy systems, whereas complex mixtures typically require a gas chromatography (GC) system [10,11,12]. GC techniques are beneficial and reliable in the analysis of complicated mixture gases in the aforementioned applications.…”

Section: Introductionmentioning

confidence: 99%

Development of Open-Tubular-Type Micro Gas Chromatography Column with Bump Structures

Lee

Lim

2019

Sensors

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Gas chromatography (GC) is the chemical analysis technique most widely used to separate and identify gas components, and it has been extensively applied in various gas analysis fields such as non-invasive medical diagnoses, indoor air quality monitoring, and outdoor environmental monitoring. Micro-electro-mechanical systems (MEMS)-based GC columns are essential for miniaturizing an integrated gas analysis system (Micro GC system). This study reports an open-tubular-type micro GC (μ-GC) column with internal bump structures (bump structure μ-GC column) that substantially increase the interaction between the gas mixture and a stationary phase. The developed bump structure μ-GC column, which was fabricated on a 2 cm × 2 cm μ-GC chip and coated with a non-polar stationary phase, is 1.5 m-long, 150 μm-wide, and 400 μm-deep. It has an internal microfluidic channel in which the bumps, which are 150 μm diameter half-circles, are alternatingly disposed to face each other on the surface of the microchannel. The fabricated bump structure μ-GC column yielded a height-equivalent-to-a-theoretical-plate (HETP) of 0.009 cm (11,110 plates/m) at an optimal carrier gas velocity of 17 cm/s. The mechanically robust bump structure μ-GC column proposed in this study achieved higher separation efficiency than a commercially available GC column and a typical μ-GC column with internal post structures classified as a semi-packed-type column. The experimental results demonstrate that the developed bump structure μ-GC column can separate a gas mixture completely, with excellent separation resolution for formaldehyde, benzene, toluene, ethylbenzene, and xylene mixture, under programmed operating temperatures.

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“…ion source, mass analyzer and detector ( Figure 17). 154 In a typical MS analysis sample is introduced trough the inlet system into the ion source where compounds are ionized. Subsequently, the ions are separated according to their m/z ratio in the mass analyzer and detected in the detector.…”

Section: Mass Spectrometrymentioning

confidence: 99%

New fractionation tools targeting elusive post-translational modifications

Wierzbicka¹

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Protein phosphorylation is a reversible post-translational modification (PTM) playing a central role in numerous biological events including disease pathogenesis. Thus, the analysis of phosphoproteome is crucial for understanding cellular regulation processes and can facilitate the development of new diagnostic and therapeutic tools. Phosphoproteins are typically analyzed using liquid chromatography coupled with mass spectrometry (LC-MS) after proteolytic processing. However, phosphopeptides are notoriously difficult to analyze by LC-MS due their low abundance and transient nature. This creates a need for effective enrichment tools for phosphorylated proteins and peptides prior to mass spectrometry analysis.The work presented in this thesis is focused on development and validation of methods and tools for enrichment of phosphopeptides with the use of molecular imprinting technology. In particular, the targeted PTMs include phosphorylation on tyrosine (pTyr) and histidine (pHis).The key recognition element employed in developed synthetic receptors was 1,3-diaryl urea functional monomer FM1. This monomer is a potent hydrogen bond donor forming strong cyclic hydrogen bonds with oxyanions such as phosphates. The bias of the imprinted urea-based receptor towards different phosphorylated residues can be programmed by selection of the template. Thus, the N, C-protected phosphotyrosine and phosphonotriazolylalanine were used as templates to generate phosphotyrosine (pTyr MIP) and phosphohistidine (pHis MIP) selective molecularly imprinted polymers, respectively.The application of previously reported pTyr MIP for phosphoproteomic studies was validated on complex biological samples of the mouse brain lysate digest spiked with standard peptides and HeLa cells digested proteins. Furthermore, the pTyr MIP was developed in the format of microspherical porous 9 beads characterized by uniformly sized and shaped particles with increased surface area and pore size as well as improved binding affinity and selectivity for larger pTyr peptides (2-3 kDa). This opens the way to generation of capture materials suitable for middle-down phosphoproteomics.In response to the lack of adequate tools and methods for enrichment of acid-labile phosphohistidine peptides a pHis MIP-based approach is proposed as a solution. The method involving selective dephosphorylation of phosphoserine (pSer) peptide by alkali treatment of the sample, followed by extraction of base-stable pHis peptides with MIP was demonstrated on the sample of bovine serum albumin digest spiked with standard pSer and pHis peptides.The last part of this thesis is focused on improving the recognition of phosphopeptides in aqueous media -the natural environment of biological samples. Guided by the principles of supramolecular chemistry, novel cationic host monomers were introduced for binding phosphates by ionic hydrogen bonds. These were used to synthesize MIPs showing enhanced binding of phosphopeptides in aqueous media. 10 11 POPULÄRVETENSKAPLIG SAMMANFATTNINGMänniskok...

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A Mass Spectrometer's Building Blocks

Cited by 8 publications

References 270 publications

Scoping study to expedite development of a field deployable and portable instrument for UF6 enrichment assay

Scoping study to expedite development of a field deployable and portable instrument for UF6 enrichment assay

Development of Open-Tubular-Type Micro Gas Chromatography Column with Bump Structures

New fractionation tools targeting elusive post-translational modifications

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