Methods for Predictive Automatic Gain Control for Hybrid Mass Spectrometers

摘要

A method for mass analyzing ions comprising a restricted range mass-to-charge (m/z) ratios comprising performing a survey mass analysis using a mass analyzer to measure a flux of ions having m/z ratios within said restricted range and performing a dependent mass analysis of an optimal quantity of ions having m/z ratios within said restricted range, said optimal quantity collected for a time period determined by the measured ion flux, CHARACTERIZED IN THAT: the time period is determined using a corrected ion flux that accounts for one or more of: (a) imperfect restriction of collected ions to the range of m/z ratios, (b) inclusion of ions within the range of m/z ratios that are undetected by the survey mass analysis, (c) different mass analyzers used for the dependent and survey mass analyses, and (d) different ion pathways used during dependent and the survey mass analyses.

主权项

1. A method for performing a mass analysis of a subset of ions generated from a sample, the subset of ions comprising a restricted range mass-to-charge (m/z) ratios of the generated ions, the method comprising the steps of performing a survey mass analysis using a mass analyzer of a mass spectrometer so as to identify the restricted range of m/z ratios and to measure a flux of ions having m/z ratios within said restricted range and performing a dependent mass analysis of an optimal quantity of ions having m/z ratios within said restricted range, said optimal quantity of ions collected for a time period determined by the measured ion flux, the method CHARACTERIZED IN THAT:
the time period is determined using a corrected ion flux that is calculated from the measured flux of ions, wherein the correction accounts for, during the dependent mass analysis, one or more of: (a) imperfect restriction of collected ions to the range of m/z ratios, (b) ion collection that includes ions within the range of m/z ratios that are undetected by the survey mass analysis, (c) the use of a different mass analyzer than the mass analyzer used for the survey mass analysis, and (d) one or more ion pathways that differ from those used during the survey mass analysis.