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第九章专用仪器下面介绍一些专用质谱仪器,以便在研制和使用这些仪器时掌握它们的特点。数量最多的专用质谱仪器——质谱检漏仪,将在有关真空技术的章节中介绍。 9—1 同位素比值质谱计采用不同类型的离子源,配合一台测定同位素比值(丰度)的通用质谱计,固然可以测定周期表上所有元素的稳定同位素和部份放射性同位素,效果却不一定都好。针对某些常见的或重要的同位素,人们设计了专用的质谱仪器,取得了良好的使用效果,下面介绍的是其中几例。相对于化学分析质谱仪器而言,同位素比值质谱计的分析对象较少。前者往往需要分析多种成份,质谱比较复杂;后者一般只针对个别元素的同位素,质谱容易辨认。然而,测定同位素比值的质谱计常对下列指标提出较高的要求:
CHAPTER 9 SPECIALIZED INSTRUMENTS Here are some of the specific mass spectrometers that help them grasp their characteristics when developing and using these instruments. The largest number of dedicated mass spectrometers - mass spectrometer leak detectors, will be described in the section on vacuum technology. 9-1 Isotope Ratio Mass spectrometry using different types of ion sources, coupled with a universal isotope ratio (abundance) of the mass spectrometer, although the determination of all elements of the periodic table stable isotopes and some radioisotopes, the effect is not certain all good. For some common or important isotopes, people designed a dedicated mass spectrometer, and achieved good results, the following is a few of them. Relative to the chemical analysis of mass spectrometry instruments, isotope ratio mass spectrometry analysis of objects less. The former often need to analyze a variety of components, more complex mass spectrometry; the latter generally only for individual elements of isotopes, mass spectrometry easy to identify. However, mass spectrometers that measure isotope ratios often place high demands on the following indicators: