1P-32 PDF
イオントラップ内での予期せぬイオン分子反応
Quadrupole ion trap mass spectrometry (QIT MS) combined with electrospray ionization (ESI) is frequently used for elucidating molecular mass and structure of organic compounds. In particular, multistage tandem mass spectrometry (MSn) is an essential tool because it shows successive degradation pathways in low-energy CID. Since the residence time of analyte ions in QIT (ms) is longer than frequency factor for energy randomization (10-100 fs), unexpected events such as rearrangements and adduct formation take place in the QIT cell. Here we report the formation of hydrated adducts of amino acid(A) lithium salt ion (AOLi + Li+) and the sodium salt ion (AONa + Na+) in the storage ion and CID spectra of lithium or sodium containing precursor ions, while the potassium salt ion (AOK + K+) never gave any hydrated adduct ions.