title: Proton transfer mass spectrometry of underivatized peptides.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D002248:Carbon Monoxide; D004355:Drug Stability; D004590:Electrophoresis, Paper; D006801:Humans; D007700:Kinetics; D013058:Mass Spectrometry; D009587:Nitrogen Isotopes; D009842:Oligopeptides; D010103:Oxygen Isotopes; D010179:Pancreas; D013329:Structure-Activity Relationship; D013460:Sulfur Isotopes; D013997:Time Factors; D014361:Trypsin Inhibitors
chemical_list: D000596:Amino Acids; D009587:Nitrogen Isotopes; D009842:Oligopeptides; D010103:Oxygen Isotopes; D013460:Sulfur Isotopes; D014361:Trypsin Inhibitors; D002248:Carbon Monoxide