Patent ID: 8803083
Filing Date: 2014-08-12
Classification: H01J

Abstract:
1. A method of determining the mass-to-charge ratios of ions in a sample, the method comprising: providing a calibration sample comprising ions of different mass-to-charge ratios to a time-of-flight mass analyzer and acquiring data until an ion with a greatest time of flight is incident on an ion detector; determining a peak width for each ion species of the calibration sample after summing several time-of-flight measurements of the calibration sample to provide calibration data of peak width versus flight time; determining a data acquisition time, the data acquisition time being a predetermined fraction of the greatest time of flight; providing ions from a continuous beam of a sample to a time-of-flight mass analyzer at pulse intervals having a duration equal to the predetermined fraction of the greatest flight time; measuring a peak width and a flight time value for each of the ion species in the sample after summing the data acquired during several pulse intervals; correcting the measured flight time values according to a correlation of measured peak width values with the calibration data of peak width versus flight time; and converting the corrected flight time values into the mass-to-charge ratios.