| 摘要 |
<p>A method of calibrating a mass spectrometer comprises initially calibrating or re-calibrating the mass spectrometer at time T0 whilst measuring and preferably recording a time-of-flight or mass-to-charge ratio M0 of one or more lockmass ions. At a subsequent time T1, the time-of-flight or mass-to-charge ratio M1 of the lockmass ions is measured again and the difference between M0 and M1 is calculated. The time of flight or mass to charge ratio of ions is then adjusted by the said difference. The instrument setting of the mass spectrometer may also be adjusted accordingly. The invention compensates for instrument drift with time whilst avoiding systematic calibration error, which can arise in conventional methods when M1 is compared with the theoretical lockmass value rather than with the actual measurement M0 at the time of the initial calibration. The method may also be used for calibrating the physico-chemical properties of ions in other analytical instruments such as ion mobility, differential ion mobility or elution time.</p> |
