JPH0823554B2 - Data processing device for chromatograph / mass spectrometer - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the fields of industry, medicine, medical care, etc., which utilize a chromatograph / mass spectrometer.

[0002]

2. Description of the Related Art For example, when an unknown sample is analyzed by a gas chromatograph / mass spectrometer, it is possible to identify what kind of compound each peak appears on the chromatogram, and whether the peak is due to a single component. In some cases, it may be desirable to determine whether the peak is a non-separated peak in which multiple components are mixed. In such a case, the mass number peculiar to the peak is selected on the mass spectrum, and the mass-specific chromatogram (hereinafter referred to as mass chromatogram (MC)) and the original chromatogram (hereinafter referred to as total ion chromatogram ( TIC)) is displayed on the screen or printed out together for comparison and analysis.

[0003]

When displaying a mass chromatogram for the above purpose, each peak has a "specific mass number" (that is, a mass number that does not appear in the mass spectra of other peaks). It is important to have a mass chromatogram drawn. However, in the conventional device, there is no means for automatically selecting the "specific mass number" for each peak, and therefore, the "specific mass number" for each peak is exclusively based on the knowledge and experience of the operator. , And the mass chromatogram is drawn, there is a problem that the selection of the "specific mass number" is not objective and that it takes a long time to execute the procedure.

The present invention was made by paying attention to this problem, and the "mass number considered to be peculiar" to each peak.
It is an object of the present invention to provide a data processing device for a chromatograph / mass spectrometer, which automatically selects and displays a mass chromatogram for the mass number.

[0005]

In order to achieve the above object, a data processor for a chromatograph / mass spectrometer according to the present invention searches a database in which a large number of mass spectra of compounds are registered, A mass number database creating means that ranks each mass number in the order of low appearance frequency and stores the rank corresponding to each mass number, and for each peak on the chromatogram, the mass of the peak For the calling means for calling the spectrum and the called mass spectrum, each mass number forming the spectrum is collated with the mass number database, and the mass number specific to the peak is determined based on the appearance frequency rank. Specific mass number determining means and mass chromatogram creating means for displaying a mass chromatogram for the determined specific mass number It has characteristically a.

[0006]

The mass number database creating means searches a mass spectrum database in which a large number of mass spectra of compounds are registered, and ranks each mass number in order of the mass number having a low appearance frequency in the database. Then, the appearance frequency ranking is stored in the mass number database in association with each mass number.

A mass number having a lower appearance frequency is more effective in identifying a peak of a chromatogram.
The mass number database is created before operating the data processing device for the chromatograph / mass spectrometer, and the mass number database is operated as necessary during the operation of the data processing device for the chromatograph / mass spectrometer. The database is referenced.

The calling means operates after the operation of the data processing device for the chromatograph / mass spectrometer is started and mass spectrum data is obtained, and calls the mass spectrum of the peak for each peak of the chromatogram. The peculiar mass number determination means, for the recalled mass spectrum, calculates each mass number constituting the spectrum,
The mass number peculiar to the peak is determined based on the rank of the appearance frequency of the mass number stored in the mass number database by collating with the data of the mass number database. That is, the selection of "mass number peculiar to each peak" is automatically performed, and the selection method is objective.

The mass chromatogram creating means displays a mass chromatogram for the unique mass number determined by the unique mass number determining means.

[0010]

The present invention will be described in more detail based on the following examples. FIG. 1 is a block diagram of a chromatograph / mass spectrometer data processing apparatus according to an embodiment of the present invention. This apparatus comprises a gas chromatograph mass spectrometer (GC / MS) 1, a computer 2 for analyzing and processing an unknown sample based on data from the gas chromatograph mass spectrometer 1, a gas chromatograph mass spectrometer 1 and a computer. It is composed of an interface (I / F) 3 for connecting to 2 and a display 4 and a printer 5 for displaying a chromatogram and the like.

The computer 2 is provided with a storage device (not shown), and a mass number database is created in advance. As illustrated in FIG. 3, the mass number database refers to a database in which the degree of importance is stored as word data for each mass number (mass number 1 to mass number n). Here, the importance refers to a rank representing the effectiveness in identifying each peak of a chromatogram, for example, by searching a commercially available mass spectrum database (for example, one published by US NIST) and The frequency of appearance of mass numbers is calculated and ranked in ascending order of frequency. The mass number database may be created by the same method as described above based on the original mass spectrum database created independently.

FIG. 2 is a flow chart showing an operation procedure of the data processing device for a chromatograph / mass spectrometer having the above-mentioned configuration. Hereinafter, description will be given with reference to FIG.
The computer 2 detects all peaks from the measured total ion chromatogram and stores the scan numbers of the start point, peak top, and peak end point of each peak (step ST (hereinafter abbreviated as ST) 1 ).

Next, the computer 2 retrieves the mass spectrum of each peak detected in the process of ST1 from a storage device (not shown) (ST2). Here, as the mass spectrum, a mass spectrum at the peak top, a mass spectrum obtained by averaging all mass spectra from the peak start point to the end point, or a background obtained by subtracting the mass spectrum at the peak start point from these mass spectra The erased mass spectrum can be arbitrarily selected.

When the mass spectrum for each peak is called out by the process of ST2, the mass number database is searched for all mass numbers which appear in each mass spectrum and have a relative intensity equal to or more than a predetermined value. Then, the degree of importance of each mass number is obtained, and the mass number having the highest degree of importance (that is, the frequency of appearance is low) is selected for each peak as the "specific mass number" (ST3). A plurality of "specific mass numbers" may be selected.

Subsequently, the computer 2 creates a mass chromatogram for the mass number selected in the process of ST3 and displays it on the display 4 or the like (ST4).

[0016]

As described above, the data processing device for a chromatograph / mass spectrometer according to the present invention obtains the importance of each mass number in advance and stores it in the mass number database. When creating a mass chromatogram, the "mass number peculiar to each peak" is automatically determined. That is, since the mass number at the time of creating a mass chromatogram is automatically determined at high speed and is always determined according to the same criterion, it is possible to reduce the time required for data analysis and improve accuracy.

[Brief description of drawings]

FIG. 1 is a block diagram of a data processing device for a chromatograph / mass spectrometer according to an embodiment of the present invention.

2 is a flow chart for explaining the operation of the apparatus of FIG.

FIG. 3 is a diagram showing a data structure of a mass number database.

[Explanation of symbols]

 ST2 Calling means ST3 Unique mass number determining means ST4 Mass chromatogram creating means

Claims (1)

[Claims] 1. A database in which a large number of mass spectra of compounds are registered is searched, and each mass number is ranked in order of the mass frequency with the lowest appearance frequency, and the rank is stored in correspondence with each mass number. The mass number database creating means, the calling means that calls the mass spectrum of the peak for each peak on the chromatogram, and the mass numbers that compose the spectrum of the called mass spectrum A unique mass number determining means for determining a unique mass number of the peak based on the appearance frequency rank by collating with a database, and a mass chromatogram creating means for displaying a mass chromatogram for the determined unique mass number. A data processing device for a chromatograph / mass spectrometer, comprising: