User:Curiouschemist/sandbox

Higher-energy collisional dissociation (HCD, formerly higher-energy C-trap dissociation) is a fragmentation technique, often used for peptide modification analysis. Immonium ions generated via HCD pinpoint modifications such as phosphotyrosine with very high confidence. An added octopole collision cell facilitates de novo sequencing.[1] Frequently, this type of dissociation is used in conjunction with Orbitrap. In this type of arrangement, the ions pass through a C trap into the HCD's multipole arrangement where the dissociaiton takes place. Then the ions can be returned to the C-trap and injected in to the orbitrap mass analyzer.

Advantages
According to thermo scientific, the HCD can be extreamly useful in quantification studies like those using Tandem Mass Tags (TMT) or Isobaric Tagging for Realtive and Absolute Quantitation (iTRAQ) tags. Because of its position in the instrumental layouts available, it is complimentary to CID in many cases.[2]