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1.
Artigo em Inglês | MEDLINE | ID: mdl-24211802

RESUMO

A portable mass spectrometer with an electron cyclotron resonance ion source (miniECRIS-MS) was developed. It was used for in situ monitoring of trace amounts of chemical warfare agents (CWAs) in atmospheric air. Instrumental construction and parameters were optimized to realize a fast response, high sensitivity, and a small body size. Three types of CWAs, i.e., phosgene, mustard gas, and hydrogen cyanide were examined to check if the mass spectrometer was able to detect characteristic elements and atomic groups. From the results, it was found that CWAs were effectively ionized in the miniECRIS-MS, and their specific signals could be discerned over the background signals of air. In phosgene, the signals of the 35Cl+ and 37Cl+ ions were clearly observed with high dose-response relationships in the parts-per-billion level, which could lead to the quantitative on-site analysis of CWAs. A parts-per-million level of mustard gas, which was far lower than its lethal dosage (LCt50), was successfully detected with a high signal-stability of the plasma ion source. It was also found that the chemical forms of CWAs ionized in the plasma, i.e., monoatomic ions, fragment ions, and molecular ions, could be detected, thereby enabling the effective identification of the target CWAs. Despite the disadvantages associated with miniaturization, the overall performance (sensitivity and response time) of the miniECRIS-MS in detecting CWAs exceeded those of sector-type ECRIS-MS, showing its potential for on-site detection in the future.


Assuntos
Ar/análise , Substâncias para a Guerra Química/análise , Cianeto de Hidrogênio/análise , Espectrometria de Massas/instrumentação , Gás de Mostarda/análise , Fosgênio/análise , Ciclotrons/instrumentação , Desenho de Equipamento , Sensibilidade e Especificidade
2.
Artigo em Inglês | MEDLINE | ID: mdl-21242103

RESUMO

We developed a detection technology for vapor forms of chemical warfare agents (CWAs) with an element analysis system using an electron cyclotron resonance ion source. After the vapor sample was introduced directly into the ion source, the molecular material was decomposed into elements using electron cyclotron resonance plasma and ionized. The following CWAs and stimulants were examined: diisopropyl fluorophosphonate (DFP), 2-chloroethylethylsulfide (2CEES), cyanogen chloride (CNCl), and hydrogen cyanide (HCN). The type of chemical warfare agents, specifically, whether it was a nerve agent, blister agent, blood agent, or choking agent, could be determined by measuring the quantities of the monatomic ions or CN(+) using mass spectrometry. It was possible to detect gaseous CWAs that could not be detected by a conventional mass spectrometer. The distribution of electron temperature in the plasma could be closely controlled by adjusting the input power of the microwaves used to generate the electron cyclotron resonance plasma, and the target compounds could be detected as molecular ions or fragment ions, enabling identification of the target agents.


Assuntos
Substâncias para a Guerra Química/análise , Ciclotrons/instrumentação , Íons/química , Espectrometria de Massas/instrumentação , Espectrometria de Massas/métodos , Gases/análise , Humanos , Micro-Ondas
3.
Eur J Mass Spectrom (Chichester) ; 13(4): 239-48, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17942974

RESUMO

The ionization efficiency of an electron cyclotron resonance ion source (ECRIS) is generally high, and all elements can be fundamentally ionized by the high-temperature plasma. We focused our attention on the high potentiality of ECRIS as an ion source for mass spectrometers and attempted to customize the mass spectrometer equipped with an ECRIS. Precise measurements were performed by using an ECRIS that was specialized and customized for elemental analysis. By using the charge-state distribution and the isotope ratio, the problem of overlap such as that observed in the spectra of isobars could be solved without any significant improvement in the mass resolution. When the isotope anomaly (or serious mass discrimination effect) was not observed in ECR plasma, the system was found to be very effective for isotope analysis. In this paper, based on the spectrum (ion current as a function of an analyzing magnet current) results of low charged state distributions (2+, 3+, 4+, ...) of noble gases, we discuss the feasibility of an elemental analysis system employing an ECRIS, particularly for isotopic analysis. The high-performance isotopic analysis obtained for ECRIS mass spectrometer in this study suggests that it can be widely applied to several fields of scientific study that require elemental or isotopic analyses with high sensitivity.

4.
Artigo em Inglês | MEDLINE | ID: mdl-18192729

RESUMO

We examined the fragmentation and ionization of molecules by low-temperature electrons generated by electron cyclotron resonance (ECR) plasma. We examined several types of metallocene compounds comprising a metal and 1,3-cyclopentadienes as ligands. We performed analyses using an ECR ion source (ECRIS) mass spectrometer. Consequently, we succeeded in ionizing fragments of an organometallic compound by adjusting the input power of the microwave introducing a super high-frequency plasma. Moreover, we succeeded in dynamically generating a significant quantity of fragment ions by continuously varying the input power. Information on the structure of a molecule may be acquired from this operation. Moreover, a molecule that could not be easily ionized thus far may now be ionizable when soft ionization is performed with this technique.

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