b-ion

{
  "id": "MLC-T-CHM-001308",
  "term": "b-ion",
  "field": "Chemistry",
  "definition": "A peptide fragment ion that contains the N-terminus, formed when a protonated peptide dissociates at the backbone amide bond between the carbonyl carbon and the nitrogen, with the charge retained on the N-terminal piece. The ion ends in the carbonyl group of the last residue it contains. Its mass equals the sum of the residue masses of its amino acids plus one proton, and it lies 28 u above the matching a-ion.",
  "subject": "Analytical Chemistry",
  "references": [
    "PAC, 2013, 85, 1515. 'Definitions of terms relating to mass spectrometry (IUPAC Recommendations 2013)' on page 1525 (https://doi.org/10.1351/PAC-REC-06-04-06)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/b-ion/"
}