Patent ID: 8735807

Claim:
A method of scanning a beam mass spectrometer comprising: generating ions from a sample; and repeatedly performing, across a chromatographic peak, the steps of: (i) mass analyzing and detecting the ions in order of their mass-to-charge (m/z) ratios from a first m/z ratio to a second m/z ratio; and (ii) mass analyzing and detecting the ions in order of their m/z ratios from the second m/z ratio to the first m/z ratio, wherein each of the mass analyzing of the ions in order of their m/z ratios from the first m/z ratio to the second m/z ratio and the mass analyzing the ions in order of their m/z ratios from the second m/z ratio to the first m/z ratio comprises a series of non-constant dwell times, wherein the dwell times vary according to a periodic function such that each repetition of the combined steps (i) and (ii) corresponds to a single period of the periodic function and wherein extrema of the periodic function correspond to the first and second m/z ratios and such that the dwell times at both the first and second m/z ratios are greater than the dwell times midway between the first and second m/z ratios.