Linked from
The 11 pages that link to Tandem mass spectrometry, each with the reason it gives.
ProteomicsBroader topic: Peptide-fragment spectra help identify proteins after enzymatic digestion.
HomocystinuriaRelated: Newborn programs use it to measure methionine, a marker for some cases.
ProteomeBroader topic: Fragment patterns help identify peptides and infer their parent proteins.
Metabolic disorderRelated: It can detect characteristic metabolite patterns in newborn screening.