Fourier transform quadrupole calibration method

Abstract

In one aspect, a method of calibrating a Fourier Transform (FT) multipole mass spectrometer is disclosed, which comprises measuring a plurality of secular frequencies of a calibrant ion in a multipole FT mass analyzer for a plurality of RF voltages (V) applied to at least one rod of the multipole mass analyzer, calculating Mathieu β and q parameters for each of 5 the measured secular frequencies, and determining RF voltage amplitude (V) for each calculated q parameter. For each calculated q parameter, an offset RF voltage amplitude (ΔV) corresponding to a deviation of the applied Vand the calculated Vis determined so as to generate a ΔVv.s. q calibration curve.