## Abstract

Real-time experiments involving fragmentation of the precursor molecular ion of n-butylbenzene (m/z 134) to produce product ions C_{7}H ^{+}_{7}, (m/z 91) and C_{7}H^{+}_{8} (m/z 92), were used to observe the motion of ions in a commercial quadrupole ion trap. Initially, ghost resonance peaks were observed for excitation of the precursor ion at q_{z} values of 0.4 and 0.5 on the q_{z} axis of the stability diagram. Further experiments involving the generation of two-dimensional contour plots confirmed that these ghost peaks, which were in agreement with mathematical equations describing the motion of ions in a quadrupole field, arose due to waveboard artifacts. Two-dimensional contour surface plots showed non-linear secular frequency canyons from a q_{z} value of 0.5 to higher values corresponding with higher drive radio frequency (rf) voltages on the stability diagram. This observation confirmed that ions are subjected to non-linear effects in this mass scan range. The octapole and hexapole field lines were observed at q_{z} values of 0.65 and 0.78, respectively.

Original language | English |
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Pages (from-to) | 15-21 |

Number of pages | 7 |

Journal | European Journal of Mass Spectrometry |

Volume | 11 |

Issue number | 1 |

DOIs | |

State | Published - 2005 |

## Keywords

- Ion trap
- Multipole fields
- Non-linear
- Precursor ions
- Product ions
- Quadrupole
- Resonance
- Secular frequency
- Stability diagram

## ASJC Scopus subject areas

- Atomic and Molecular Physics, and Optics
- Spectroscopy