20: Molecular Mass Spectrometry
- Page ID
- 333373
\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\)
- 20.1: Molecular Mass Spectra
- In Chapter 11 we considered the use of mass spectrometry in the analysis of atoms. In this chapter we turn our attention to the use of mass spectrometry for the analysis of molecules.
- 20.2: Ion Sources
- Since a mass spectrum shows the relative abundance of ions with different mass-to-charge ratios, a mass spectrometer must include a way to generate ions. More specifically, it needs a method that generates the initial ion as it, once formed, will undergo fragmentation without additional help from the analyst. In this section we consider several common ion sources.
- 20.3: Mass Spectrometers
- A mass spectrometer has four essential elements: a means for introducing the sample to the instrument, a means for generating a mixture of ions, a means for separating the ions, and a means for counting the ions. In Chapter 20.2 we introduced some of the most important ways to generate ions. In this section we turn our attention to sample inlet systems and to separating and counting ions.
- 20.4: Applications of Molecular Mass Spectrometry
- In a qualitative analysis our interest is in determining the identity of a substance of interest to us. By itself, mass spectrometry is a powerful tool for determining the identity of pure compounds. The analysis of mixtures, however, is possible if we use a mass spectrometer as both a qualitative and quantitative detector for a separation technique, such as gas chromatography, or if we string together two or more mass analyzers in sequence.