JP2995841B2 - Gas chromatograph mass spectrometer data processor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention automatically generates a mass chromatogram showing a change over time of an ion intensity having a specific mass number based on a mass spectrum obtained by a gas chromatograph mass spectrometer. The present invention relates to a data processing device that creates, outputs, and displays data.

<Prior Art> Generally, when a qualitative or quantitative analysis of a sample is performed using a gas chromatograph mass spectrometer, a component substance may be analyzed by displaying a mass chromatogram (MC). This mass chromatogram (MC) is obtained by measuring the mass spectrum of a sample whose components have been separated by gas chromatography, repeating mass scanning with a mass spectrometer at regular time intervals, and then analyzing the substance to be analyzed from these mass spectra. The change over time of the ion intensity of the specific mass number is displayed or recorded on a chart.

If this mass chromatogram is used, components having peaks that cannot be separated by a gas chromatograph can be separated by mass number, so that there is an advantage that analysis accuracy is improved.

By the way, in order to obtain a mass chromatogram corresponding to each mass number, it is necessary to individually specify the mass number (mass number number) of the component substance to be analyzed. The designation of the number was manually input to a computer or the like. Specifically, a total ion chromatogram (TIC) showing the time-dependent change of the total ion intensity is created based on the data of the mass spectrum stored in advance, and the characteristic peak of the component contained in the component peak on the total ion chromatogram is created. Is set and input by the operator.

<Problems to be Solved by the Invention> However, there is a problem that it takes time and effort to individually specify the mass number of each component substance and input data.

<Means for Solving the Problems> The present invention has been made in view of the above circumstances, and automatically determines a mass number which has conventionally been set and input manually and responds to each of the mass numbers. Thus, the labor of the input operation is reduced by obtaining a mass chromatogram.

Therefore, in the data processing device of the gas chromatograph mass spectrometer of the present invention, mass spectrum storage means for storing data of each mass spectrum obtained by mass scanning at predetermined time intervals by the gas chromatograph mass spectrometer,
For each mass spectrum data, a base peak detecting means for detecting a base peak indicating the maximum value of the ion intensity contained in the data, and a base for storing a mass number of the base peak detected by the base peak detecting means, respectively. Peak storage means, based on the mass number of each base peak stored in the base peak storage means, from the data of the mass spectrum stored in the mass spectrum storage means, the ion intensity corresponding to each mass number Data reading means for reading in time series, and output means such as a display and a printer for outputting a mass chromatogram indicating a temporal change of the ion intensity read by the data reading means are provided.

<Operation> In the above configuration, all mass spectrum data obtained by mass scanning at predetermined time intervals by the gas chromatograph mass spectrometer are all stored in the mass spectrum storage means. Further, since the data of each mass spectrum is sent to the base peak detecting means, the base peak detecting means detects the base peak indicating the maximum value of the ion intensity contained in the data of each mass spectrum. Then, the mass numbers corresponding to these respective base peaks are stored in the base peak storage means. When the measurement of the mass spectrum is completed, the data reading means then outputs the data of the mass spectrum stored in the mass spectrum storage means based on the mass number of each base peak stored in the base peak storage means. , The ion intensity corresponding to each mass number is read out in time series. And
The change over time of the ion intensity of the unique mass number is output as a mass chromatogram to an output unit such as a display or a printer.

<Example> FIG. 1 is a block diagram of a data processing device of a gas chromatograph mass spectrometer.

In FIG. 1, reference numeral 1 denotes a gas chromatograph mass spectrometer, and 2 denotes a data processing device for processing data of each mass spectrum obtained by performing mass scanning at predetermined time intervals by the gas chromatograph mass spectrometer 1. 4 is an interface, 6 is a mass spectrum storage means (RAM in this example) for storing mass spectrum data inputted via the interface 4, and 8 is an ion intensity data contained in each mass spectrum data. Base peak detecting means 10 for detecting a base peak indicating the maximum value, and 10 a base peak storing means (RAM in this example) for storing the mass numbers of the base peaks detected by the base peak detecting means 8, respectively. The mass spectrum storage means 6 and the base peak storage means 10 can be shared by using a single RAM and dividing its storage area.

Reference numeral 12 denotes a time series of the ion intensity corresponding to each mass number from the mass spectrum data stored in the mass spectrum storage means 6 based on the mass number of each base peak stored in the base peak storage means 10. This is a data reading means for reading out the data, and in this example, comprises a CPU. 1
Reference numeral 4 denotes a TIC display signal generator for generating a display signal of a total ion chromatogram indicating a temporal change of the total ion intensity read by the data read means 12, and 16 denotes a data read means 12
MC that generates a display signal of a mass chromatogram showing the change over time of the ion intensity of a specific mass number read out at
The display signal generation unit 18 is an output unit that outputs the display signal generated by the display signal generation units 14 and 16, and is constituted by a display in this example. It should be noted that a printer can be used in place of the display 18 of this example.

Next, the operation of each part of the above configuration will be described with reference to FIG. 2 and FIG.

Since the CPU 12 outputs a mass scanning control signal to the gas chromatograph mass spectrometer 1 at a constant time interval, the mass spectrometer 1 is mass-scanned by this control signal and ions are mass-separated. As shown, for a certain time
Mass spectra are obtained at t ₁ ,..., ti,. The data of each of these mass spectra is stored in interface 4
Are sequentially stored in the mass spectrum storage means 6.

In parallel with this, the data of each mass spectrum is
It is sent to the base peak detecting means 8. The base peak detecting means 8 detects a base peak indicating the maximum value of the ion intensity contained in the data of each mass spectrum. For example, in the time t ₁ peak indicated by reference numeral p ₁ is the peak of pi at time ti is, pn peak at time tn is maximum base peak, respectively. Then, the mass numbers m ₁ ,…, corresponding to these respective base peaks p ₁ ,…, pi,…, pn
.., mn are stored in the base peak storage means 10 at the next stage.

If measurement of all mass spectrum by elapsed from time t ₁ ~ time tn has been completed, then, CPU 12 is in each time based on the data of mass spectrum stored in the mass spectrum storage means 6 Read out in chronological order while integrating the total ion intensity. Since this data is sent to the TIC display signal generator 14 as display data of the total ion chromatogram, the TIC display signal generator 14
A display signal of the total ion chromatogram is generated based on the data, and is output to the display 18.

Further, the CPU 12 calculates the mass numbers m ₁ ,..., Mi,... Mn of each base peak stored in the base peak storage means 10.
From the mass spectrum data stored in the mass spectrum storage means 6, each of the mass numbers m ₁ ,
, Mi, ..., mn are read out in chronological order from the data of the ion intensity. Since this data is sent to the MC display signal generation unit 16 as display data of the mass chromatogram,
The MC display signal generator 16 generates a display signal of the mass chromatogram based on the data, and outputs this to the display 18.

As a result, as shown in FIG. 3, the display 18 shows a total ion chromatogram (see FIG. 3 (a)) showing the change over time of the total ion intensity, and the base peak of the base ion corresponding to this. A mass chromatogram (see FIG. 8B) indicating the temporal change of the ion intensity separated for each of the mass numbers m ₁ ,..., Mi,..., Mn is simultaneously displayed on the same screen.

<Effects of the Invention> According to the present invention, a mass chromatogram having a base peak as a mass number is automatically obtained, so that it is not necessary to manually input a mass number as in the related art, and analysis can be performed. Time can be reduced. In particular, this is effective when obtaining a mass chromatogram for a multi-component sample.

[Brief description of the drawings]

Drawings show an embodiment of the present invention, FIG. 1 is a block diagram of a data processing device of a gas chromatograph mass spectrometer,
FIG. 2 is an explanatory diagram showing a mass spectrum obtained by performing mass scanning at predetermined time intervals with a gas chromatograph mass spectrometer;
FIG. 3 is an explanatory diagram showing a total ion chromatogram obtained by the apparatus of FIG. 1 and a mass chromatogram for each mass number. DESCRIPTION OF SYMBOLS 1 ... Gas chromatograph mass spectrometer, 2 ... Data processing apparatus, 6 ... Mass spectrum storage means, 8 ... Base peak detection means, 10 ... Base peak storage means, 12 ...
Data reading means, 18 ... output means.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01J 49/00-49/48 G01N 27/62

Claims (1)

(57) [Claims] 1. A mass spectrum storage means (6) for storing mass spectrum data obtained by mass scanning at predetermined time intervals by a gas chromatograph mass spectrometer; and for each of said mass spectrum data, Base peak detecting means (8) for detecting a base peak indicating the maximum value of the contained ion intensity, and base peak storing means (10) for storing the mass numbers of the base peaks detected by the base peak detecting means (8), respectively. ) And, based on the mass numbers of the respective base peaks stored in the base peak storage means (10), correspond to the respective mass numbers from the mass spectrum data stored in the mass spectrum storage means (6). Data reading means (12) for reading out the ion intensity to be performed in time series, and the data reading means (12) Display for outputting a mass chromatogram showing the time course of which Desa viewed ionic strength,
A data processing device for a gas chromatograph mass spectrometer, comprising: output means (18) such as a printer.