论文部分内容阅读
在质谱学中经常会遇到“分辨本领”这个术语。分辨本领就是质谱仪器分离不同质荷比离子谱峰的能力,这是公认的概念,没有任何疑问。但是怎样才算“把谱峰分开了”或“可分辨”的定义,至今还有问题。本文在介绍了目前流行的三种定义和测试方法后,还讨论了它们在量测实际谱峰时的局限性。强调了仔细研究实际峰形的必要性。然而至今仍然广泛使用着不同定义的分辨本领指标,因而在比较仪器的实际性能时经常遇到困难。本文举例讨论了这方面的问题,并指出了解决的途径。对一些典型的峰形,特别对“高斯峰”给出了不同定义分辨本领的转换系数。本文讨论的问题同样适用于其它谱仪(如电子能谱仪)。在质谱学中,我们经常会遭到“分辨本领”或“质量分辨本领”这个术语。它是质谱仪器最重要的总体指标之一,又与仪器的灵敏度有密切的联系。我们知道,任何一种质谱仪器都是使带电粒子在电磁场中运动,并在运动过程中把它们按质荷比分开,从而达到测定“质谱”的目的。表征质谱仪器分离不同质荷比离子谱峰能力的指标就叫做“分辨本领”。这是公认的概念,没有任何的疑问。如果仪器能把质量数为 M 和 M+△M 两种离子分开,这时仪器的分辨本领就是(M/△M),可记作 R=(M/△M);或者说这时仪器的绝对分辨本领是△M。例如一台质谱计可将质量数100和101两种离子分开,这时 M=100,△M=1,则可以说它的分辨本领 R=100;或者说它的绝对分辨本领△M=1。但是怎样才算“把谱峰分开了”或者说“可分辨”的定义,至今却还有问题。目前流行有三种定义方法,它们都有一定的局限性,有时甚至在比较实际仪器的性能时会产生一些混乱,因此有必要进行深入的讨论。
In mass spectrometry often encounter the “ability to resolve” the term. The ability to distinguish is the ability of mass spectrometers to separate peaks of different mass-to-charge ratios, which is a well-accepted concept without any doubt. However, there are still some problems as to the definition of “separating peaks” or “distinguishable”. After introducing the three popular definitions and testing methods, this article also discusses their limitations when measuring the actual peak. The need to study the actual peak shape is emphasized. However, different definitions of resolving power indicators are still widely used to date and therefore often encounter difficulties in comparing the actual performance of the instrument. This article gives an example to discuss this issue, and points out the solution. For some typical peak shapes, especially the “Gaussian peak” is given a different definition of resolving power conversion factor. The problems discussed in this article also apply to other spectrometers (such as electron spectrometers). In mass spectrometry, we often come across the term “resolution skills” or “mass resolution skills.” It is one of the most important general indicators of mass spectrometry instruments and closely linked to the sensitivity of the instrument. We know that any mass spectrometry instrument is to make the charged particles move in the electromagnetic field and separate them by the mass-to-charge ratio during the movement so as to achieve the purpose of measuring “mass spectrometry”. Characterization of mass spectrometer instrument separation of different mass-to-charge ratio peak ion power index is called “resolution skills.” This is a recognized concept without any doubt. If the instrument can separate the mass of M and M + △ M two ions, then the resolution of the instrument is (M / △ M), can be recorded as R = (M / △ M); or at this time the absolute instrument Discrimination skills is △ M. For example, a mass spectrometer can separate the mass of two kinds of ions 100 and 101, then M = 100, △ M = 1, then it can be said that the resolution of R = 100, or its absolute resolution △ M = 1 . However, there are still some problems as to how to define the definition of “distinguishable peaks” or “distinguishable”. Currently there are three ways to define the prevalence, they have some limitations, and sometimes even when the actual performance of the instrument will produce some confusion, it is necessary to conduct an in-depth discussion.