US 2006/0219890 A1 · Time of flight mass spectrometer

Abstract

The present invention relates to a time of flight mass spectrometer (TOFMS) having a flight space in which ions to be analyzed repeatedly fly in a loop orbit or reciprocal path. In an example of the present invention, the TOFMS carries out two rounds of measurement for one sample under two conditions differing in the effective flight distance of the ions to create two flight time spectrums. The data processor of the TOFMS compares the central points of the peaks in the two spectrums to identify peaks that have resulted from the same kind of ion (Step S3). If any peak is found to be unidentifiable (“No” in Step S4), the data processor examines the similarity of the peak shapes (e.g. half-value width) to identify peaks that have resulted from the same kind of ion (Step S5). After the correspondence of all the peaks have been determined, the data processor calculates the approximate mass to charge ratio of each ion from the difference in flight time (Step S6) and determines the number of turns of the ion based on the approximation (Step S7). Finally, it calculates the exact mass to charge ratio, using the number of turns and the flight time (Step S8). Thus, even if the sample contains many components and the spectrums accordingly have many peaks mixed together, the TOFMS can identify all the peaks.

Claims13

Dependent claims

A time of flight mass spectrometer for separately detecting different kinds of ions with respect to their mass to charge ratios by releasing the ions from an ion source, making them fly substantially along the same track once or multiple times repeatedly, and then introducing them into a detector, comprising:

a) a measuring system for measuring flight times of the ions under at least two conditions differing in an effective flight distance between a point where the ions leave the ion source and a point where the ions enter the track or between a point where the ions leave the track and a point where the ions reach the detector, or differing in a state of a force acting within a field for accelerating or decelerating the ions traveling through the field;
b) a peak identifier for comparing shapes of peaks in at least two flight time spectrums obtained through measurements with the measuring system and for identifying peaks resulting from the same kind of ion;
and
c) a processor for calculating a difference in the flight time between peaks that the peak identifier has identified as resulting from the same kind of ion, and for estimating the mass to charge ratio of an ion from the difference in the flight time.

1 more element

a) a measuring system for measuring flight times of the ions under three conditions differing in the effective flight distance between a point where the ions leave the ion source and a point where the ions enter the track or between a point where the ions leave the track and a point where the ions reach the detector, or differing in a state of a force acting within a field for accelerating or decelerating the ions traveling through the field;
b) a peak identifier for locating peaks resulting from the same kind of ion by selecting two peaks on a supposition that they have resulted from the same kind of ion among all peaks in two of three flight time spectrums created from measurement data obtained with the measuring system, predicting a position at which another peak resulting from the same kind of ion should exist on the other flight time spectrum if the aforementioned supposition is correct, and determining whether a peak actually exists at the predicted position;
and
c) a processor for calculating a difference in the flight time between peaks that the peak identifier has identified as resulting from the same kind of ion, and for estimating the mass to charge ratio of the ion from the difference in the flight time.

1 more element

Dependencies are inferred from the claim text.

Time of flight mass spectrometer

Life of this patent

Time of flight mass spectrometer

Life of this patent

Abstract

Claims13