Question

What is the difference between mass spectrometry (MS) and tandem mass spectrometry(MS-MS)?

Answer 1

Mass spectrometry (MS) is an analytical technique that measures the mass-to-charge ratio of ions. The results are typically presented as a mass spectrum, a plot of intensity as a function of the mass-to-charge ratio.

Mass spectrometry/mass spectrometry (MS/MS), or tandem mass spectrometry, is a procedure for improving the specificity of the mass spectrometer. When 2 mass analyzers are coupled with each other by using a collision cell we call them MS/MS or in tandem MS. Use of two mass analyzers increases the specificity and helps us in detecting targeted proteins. In this case, one analyzer depends on the data of the other, hence also called as data-dependent. The MS system can be run in different modes, dependin upon the application. Say, for example, only one analyzer working at a time, or both working in a data-dependent fashion or both working independently and then the comparison of both, etc.