Agilent Technologies, Inc.

James Drewry Foote

Stuart Carl Hansen

Harry F Prest

Randy Keith Roushall

Methods, systems and computer readable media for dynamically controlling a time period of ion detection by an ion detector of a mass spectrometer. A current resulting from conversion of an output of the detector is surveyed during the ion detection by the detector. The time period for the ion detection is terminated upon calculation of a statistically valid accumulation statistic, calculation indicating that satisfactory statistics cannot be achieved over the time period, relative to a predetermined statistical threshold, or elapsing of the entire time period having been preset.

Dynamic adjustment of ion monitoring periods

An apparatus for electronically controlling a quadrupole in a mass spectrometer, comprises radio frequency (RF) drive circuitry and direct current (DC) drive circuitry coupled to a quadrupole, an RF control loop associated with the RF drive circuitry, a DC control loop associated with the DC drive circuitry, and control loop circuitry associated with the DC control loop, the control loop circuitry configured to alter a response of the DC control loop during a settling time period of a step response such that ion transmission through the quadrupole is greater during the settling time than if the response of the DC control loop during the settling time is unaltered.

Apparatus and method for electronically driving a quadrupole mass spectrometer to improve signal performance at fast scan rates

An ion acceleration apparatus and method, and a mass spectrometer using the apparatus and method, require only a single pulse generator for the collection and acceleration of ions. The apparatus, method and mass spectrometer are useful in time-of-flight mass spectrometry (TOFMS). The apparatus, method and spectrometer save on manufacturing costs and complexity, without compromising measurement sensitivity or reliability. The ion acceleration apparatus comprises a plurality of conductive plates comprising a pulser electrode, three grids and preferably, a plurality of frames units, in a stacked relationship. The pulser electrode and a third grid form the outside ends of the ion acceleration apparatus. The plates of the stack are spaced apart and electrically insulated from one another. A power source provides fill, pulse and bias voltages to the plates. The power source comprises a pulse generator that provides fill and pulse voltages to the pulser electrode and to a first grid that is adjacent to the pulser electrode. A second grid is electrically connected to ground potential and is between the first grid and the plurality of guard frames. The power source further comprises a voltage source for supplying a fixed high voltage bias to the third grid and preferably to the frame units. During the fill period, analyte ions from an ion source are collected in a fill region between the pulser electrode and the first grid. The pulser electrode and first grid are supplied with a small magnitude voltage of a polarity opposite to a polarity of a charge of the analyte ions. During the pulse period, the analyte ions are induced to move from the fill region and into an acceleration region by the application of the pulse voltage to the pulse electrode and the first grid. The pulse voltage is a large magnitude voltage of the same polarity as the polarity of the charge on the analyte ions. A field produced by the fixed voltage bias applied to the third grid and guard frames accelerates the analyte ions once they enter the acceleration region.

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Sunnyvale, CA, United States of America

James Drewry Foote