US 6,723,983 B2 · High throughput of laser desorption mass spectra in time-of-flight mass spectrometers

Abstract

The invention relates to a time-of-flight mass spectrometer for acquiring spectra of either primary or daughter ions with high mass precision. All the periodic voltage pulse sequences used in the mass spectrometer—in the ion source, and any precursor ion selector or post-acceleration unit—are run continuously at a fixed base frequency, independently of whether a spectrum is being acquired in the relevant period, in order to avoid any disturbance of the electrical and thermal equilibrium. Ignition delay of the laser after triggering is controlled by switching the output of the clock pulse. The voltage pulse sequences, moreover—once again to avoid settling times—are to be designed in such a way that their voltages and delay times are entirely independent of the mass of the precursor ions. This feature can be achieved through appropriate forming of the delayed ion acceleration voltage pulse.

Claims21

Dependent claims

Method for the measurement of laser desorption mass spectra with high operational stability in a time-of-flight mass spectrometer with delayed ion acceleration, the method comprising the steps of:

(a) providing a time-of-flight mass spectrometer with a pulse generator that generates voltage pulses, in response to a pulse tripper signal, that are delivered to an electrode of the spectrometer for the control of the delayed ion acceleration;
(b) providing a pulse laser system that generates a laser pulse in response to a laser trigger signal, and that outputs a pulse trigger signal to the pulse generator once a laser light pulse is generated;
(c) generating a clock signal having a frequency corresponding to a frequency of spectrum acquisition or a multi pie thereof;
and
(d) directing the clock signal with a switch to either to the pulse laser system or to the pulse generator, the clock signal being directed to the pulse generator as a pulse trigger signal during waiting periods without spectrum acquisition, and being directed to the pulse laser system as a laser trigger signal at times of spectrum acquisition.

2 more elements

Dependencies are inferred from the claim text.

High throughput of laser desorption mass spectra in time-of-flight mass spectrometers

Life of this patent

High throughput of laser desorption mass spectra in time-of-flight mass spectrometers

Life of this patent

Abstract

Claims21