What does CID stand for in mass spectrometry?

In the field of mass spectrometry, CID stands for Collision Induced Dissociation. This technique is used to fragment ions into smaller pieces by colliding them with neutral gas molecules. The primary purpose of CID is to provide structural information about the ions present in the sample. When ions collide with the neutral gas, energy is imparted to them, resulting in the breaking of chemical bonds and the production of fragment ions. This allows analysts to deduce the structure of the original ion based on the mass-to-charge ratios of the resulting fragments.

Knowing the process and significance of Collision Induced Dissociation is crucial for applications involving the analysis of complex mixtures, proteomics, and the identification of unknown compounds. It plays a critical role in enhancing the capabilities of mass spectrometers by enabling tandem mass spectrometry (MS/MS) techniques, where detailed fragmentation patterns can be analyzed to provide deeper insights into the molecular structure of analytes.