共查询到20条相似文献,搜索用时 59 毫秒
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近年来,挥发性有机物(VOCs)快速、在线分析的应用需求促进了各类VOCs在线分析质谱仪的发展。本研究自行研制基于膜进样技术的小型紫外光电离飞行时间质谱仪,并阐述设计原理、性能表征及其对工作场所VOCs的检测应用。仪器采用聚二甲基硅氧烷(PDMS)作为进样界面,既保证了仪器的真空,又起到富集VOCs并降低检出限的作用。电离源使用发射10.6 eV光子的氪灯作为光源,可电离低于10.6 eV电离能的VOCs,并产生分子离子峰,这一特性便于谱图识别与高通量分析。飞行时间质量分析器采用小型化设计,总长度小于360 mm。结果表明,该仪器在m/z 170处全高半峰宽(FWHM)分辨率为2 000,苯、甲苯、对二甲苯的检出限在5×10-10~3×10-9 mol/mol之间。将该仪器用于工作场所中苯系物成分分析,取得了良好的靶向分析结果。 相似文献
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电子轰击源垂直加速式飞行时间质谱仪的研制 总被引:6,自引:3,他引:3
介绍了自制的电子轰击离子源(electron ionization, EI)垂直加速式飞行时间质谱仪(orthogonal acceleration time-of-flight mass spectrometer, Oa-TOF MS)的原理,结构以及初步的实验结果。搭建了电子轰击源垂直加速式飞行时间质谱仪,并得到室内空气成分谱图。结果表明,仪器分辨率优于2 000(full width at half maximum,FWHM),质量精度优于4×10-5,可以用于气体成分的快速定性分析。 相似文献
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一种用于飞行时间质谱仪的脉冲辉光放电离子源 总被引:2,自引:2,他引:2
介绍了一种用于飞行时间质谱仪的新型辉光放电离子源。该离子源在微秒级脉冲(瞬短脉冲)模式下工作。实验结果表明,瞬短脉冲辉光放电的电流比直流辉光放电有数量级的提高。对瞬短脉冲辉光放电离子源与质谱仪的接口的结构要求相当苛刻,必须用一块可加工陶瓷片屏蔽采样板,把采样板与辉光放电的阳极隔开,才能达到良好的真空及溅射。以黄铜为样品,瞬短脉冲辉光放电的瞬时溅射率达到24.4μg/s·mm^2。就黄铜样品的典型谱 相似文献
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高分辨电喷雾离子源三级四极杆-飞行时间质谱仪的研制 总被引:4,自引:1,他引:4
报道了实验室研制的电喷雾离子源 ,具有射频四极杆接口的高分辨飞行时间质谱 (ESI- QQQ- TOFMS)仪器。该仪器具有以下特点 :在离子调制区使用三组四极杆 ,有效地减少离子束的空间分散和能量分散 ;采用正负双脉冲推斥和离子垂直引入方式 ;经过优化设计的二级有网反射器 ;新颖的 MCP安装方法。经初步调试 ,该仪器的分辨本领已优于 1 0 ,0 0 0 ,质量测定精度优于 1 0× 1 0 - 6 。该仪器于 2 0 0 2年 6月通过了国家教育部科技成果鉴定 [鉴字 [教 2 0 0 2 ]第 0 0 8号 ],其主要性能指标已经达到了国际先进水平 相似文献
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高效液相色谱检测器——高分辨飞行时间质谱仪的研制 总被引:2,自引:0,他引:2
本文研制的质谱仪是具有电喷雾离子源和射频四极杆接口的高分辨飞行时间质谱仪(ESI-QQQ-TOF-MS)。该仪器的特点如下:采用可三维调节、带有加热雾化气的电喷雾源液质联用接口;采用由三组四极杆组成、可有效调制离子束的离子光学系统;采用正负双脉冲推斥和垂直引入方式;采用经优化设计的二级有网反射器。该仪器分辨本领优于11 000(Full Width at Half Maximum, FWHM),质量测定精度优于10×10-6,最低检测限低于3 fmol/μL。可作为高效液相色谱优良的质谱检测器。 相似文献
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The design of a compact, high-resolution 180 degrees magnetic deflection mass spectrometer for the study of positive and negative hydrogen-ion species is described. 相似文献
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A gas expansion system combined with a mass spectrometer has been tested and flown successfully in the stratosphere. Through a sequence of orifices and high speed pumping, gas particles were formed into a molecular beam and analyzed by a sensitive mass spectrometer. During two balloon flights, vertical profiles of all major atmospheric constituents as well as O(3), CO(2), H(2)O and others were obtained. Gases such as (38)Ar and (16)O(17)O provided in-flight calibration standards. The sensitivity of the system was such that gases with mixing ratios of 10 ppb at an ambient pressure of about 10 mbar were detectable. 相似文献
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A. N. Zavilopulo E. A. Mironets A. S. Agafonova 《Instruments and Experimental Techniques》2012,55(1):65-71
A model analysis of ion sources for dynamic mass spectrometers was performed, and the design of an upgraded ion source, which substantially reduces the ion energy spread, allows optimization of the zone of ion extraction from the source, and provides a high sensitivity of the instrument in the operation with low-energy ionizing electrons (down to threshold energies), was developed. Methodological techniques that allow one to analyze and calculate numerical model variants of ion sources of various designs using the SIMION 3D 7.0 program were developed. 相似文献
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T Andersen R Jensen MK Christensen T Pedersen O Hansen I Chorkendorff 《The Review of scientific instruments》2012,83(7):075105
We demonstrate a combined microreactor and time of flight system for testing and characterization of heterogeneous catalysts with high resolution mass spectrometry and high sensitivity. Catalyst testing is performed in silicon-based microreactors which have high sensitivity and fast thermal response. Gas analysis is performed with a time of flight mass spectrometer with a modified nude Bayard-Alpert ionization gauge as gas ionization source. The mass resolution of the time of flight mass spectrometer using the ion gauge as ionization source is estimated to m∕Δm > 2500. The system design is superior to conventional batch and flow reactors with accompanying product detection by quadrupole mass spectrometry or gas chromatography not only due to the high sensitivity, fast temperature response, high mass resolution, and fast acquisition time of mass spectra but it also allows wide mass range (0-5000 amu in the current configuration). As a demonstration of the system performance we present data from ammonia oxidation on a Pt thin film showing resolved spectra of OH and NH(3). 相似文献
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Zhang S Wang Y Cao Z Zhang B Wang S Kong R Zhao Y Shan X Sheng L 《The Review of scientific instruments》2007,78(4):043104
We have developed an efficient and applicable apparatus that combines mass-analyzed threshold ionization (MATI) with continuous molecular-beam mass spectrometry using tunable vacuum ultraviolet synchrotron radiation at National Synchrotron Radiation Laboratory. The new design, in which the spoiling field and the pulsed ionization field are perpendicular to each other, can obtain efficiently the ionic spectra of molecule. The MATI spectra of Ar and N(2) have been recorded in the energy region between 15.5 and 17.5 eV to illustrate the feasibility of this scheme. With its unique features, the important experiment considerations are potentially a powerful tool for study of information of ionization energies and ionic states of complex organic compounds. 相似文献
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A new design of a linear time of flight mass spectrometer (ToFMS) is implemented that gives nearly field-free interaction region without compromising on the mass resolution. The design addresses problems that would arise in a conventional Wiley-McLaren type of ToFMS: (i) field leakages into the charged particle-molecule interaction region from various components of the mass spectrometer, including that through the high transparency mesh used to obtain evenly distributed electric fields; (ii) complete collection and transportation of the ions produced in the interaction region to the detector, which is essential for high sensitivity and cross section measurements. This ToFMS works over a wide range of masses from H(+) to a few hundred Daltons and would be the most suitable for low energy charged particle-molecule interaction studies. Performance of the ToFMS has been tested by measuring the partial ionization cross sections for electron impact on CF(4). 相似文献