JP2872375B2 - Mass spectrometer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a mass spectrometer.

[Conventional technology]

A mass spectrometer is a device that ionizes a sample, separates the sample by mass by applying an electric field or a magnetic field, and analyzes the mass. Such an apparatus will be described by taking a liquid chromatograph direct-coupled mass spectrometer (hereinafter abbreviated as an LC / API mass spectrometer) using atmospheric pressure ionization (hereinafter abbreviated as an API) as an example.

FIG. 1 shows an outline of an LC / API mass spectrometer. A sample and a mobile phase eluted from the liquid chromatograph 1 (hereinafter abbreviated as LC) are sent to an atomizing section 3 through a Teflon pipe 2 and are atomized by applying heat thereto. The atomized sample and mobile phase are vaporized in the desolvation chamber 10 to be in a molecular state. The sample and mobile phase in the molecular state enter the ionization chamber 4 and are ionized by corona discharge generated from the needle electrode 5. The ionized mobile phase molecules undergo a molecular reaction with the sample molecules, and ionize the sample molecules by transferring protons to the sample molecules that have not yet been ionized. By this molecular reaction, the sample molecules are gently and almost all the molecules are ionized. The ionized sample molecules pass through the first pore electrode 6 and further pass through the second pore electrode 7 to the mass analyzer 8 where they are subjected to mass analysis.

As described above, in the mass spectrometer, the sample is introduced into the mass spectrometer, ionized after a short time, and analyzed after a short time. for that reason,
In general, the amount of an ionized sample is checked, the point in time at which the amount becomes the largest is determined, and an analysis result is obtained at that point.

[Problems to be solved by the invention]

However, in the above-described conventional technique, since the determination is made based on the amount of the ionized sample, there has been a problem that the determination is likely to be erroneous. That is, some samples are difficult to ionize, and in the case of analysis of such a sample,
The amount of the ionized sample is buried in the background noise, making it impossible to determine whether the sample corresponds to the sample to be obtained or is simply noise.

An object of the present invention is to provide a mass spectrometer capable of easily obtaining a sample analysis result.

[Means for solving the problem]

In order to achieve the above object, according to the present invention, a mass spectrometer having an ionization section for ionizing a sample and mass-separating and analyzing the ionized sample detects a sample concentration of the sample before the ionization. First detecting means, second detecting means for detecting an ion amount of the ionized sample, output of the first detecting means corresponding to a plurality of times, and output of the second detecting means corresponding to a plurality of times Are configured to have display means capable of displaying both on the same display medium at the same time.

[Action]

With the above configuration, the concentration of the sample before ionization can be displayed on the display medium, and the ion amount of the ionized sample can be displayed on the same display medium. Whether the sample is easily ionized or not can be determined based on the concentration of the sample before being ionized, and information on the sample can be obtained. As described above, the analysis result can be obtained with reference to the concentration of the sample before being ionized, and it is possible to easily determine and obtain the analysis result of the sample to be obtained. Note that the sample concentration before ionization and the ion amount after ionization are mutually time-shifted information,
Since these can be displayed on the same display medium, they can be used so as to complement each other easily, and as a result, the information of mass spectrometry can be easily obtained.

〔Example〕

Figure 2 shows the total ion chromatogram (hereinafter TIC)
An embodiment of the present invention in which a UV chromatogram and a mass spectrum are displayed on the same monitor is shown. First
The difference from the conventional method shown in the figure is that only the mass spectrum signal obtained from the mass spectrometry unit 8 as an input signal has been taken in the data processing device 9 via the A / D converter 14 so far. In FIG. 2, the UV chromatogram signal detected by the UV detector 13 is also taken into the data processing device 9 via the A / D converter 15. The captured UV chromatogram and mass spectrum signal are displayed as TIC, UV chromatogram and mass spectrum on the same monitor 16 as shown in FIG. Needless to say, the TIC is obtained by integrating all the signals of the mass spectrum obtained by one sweep of the mass spectrometer 8 by the data processor 9 and plotting the value for each sweep.

Therefore, TIC essentially gives the same chromatogram as the UV chromatogram, but not all of the sample separated and introduced from the LC is ionized, and the ionization efficiency of the sample is reduced. Since they are different, they are not the same chromatogram. Therefore, there is an advantage of the present invention in that the TIC and the UV chromatogram are displayed on the same screen. Because, when displayed on the same screen, the operator can easily find the point at which the sample is introduced into the LC / API mass spectrometer 8 from the LC1, and the TIC or UV chromatogram has the maximum peak. In that
This is because it is most preferable to display a mass spectrum.

At the point where the peak of the TIC or UV chromatograph becomes maximum, for example, by pressing the space key in the keyboard of the data processing device 9, the mass spectrum is displayed as shown in the lower part of FIG. The spectrum is displayed. Of course, changing the display width of the mass spectrum (for example, M / Z100 to 500, or M / Z200 to 1000), or mass spectrum scan number,
Alternatively, it is also possible to instruct and display a subtraction or the like of a mass spectrum serving as a background. In addition, the magnification of the TIC and UV chromatograms can be changed and displayed.

Although the present invention has been desired from an early stage, it has not been realized in conventional LC direct-coupled mass spectrometers because the TIC cannot be drawn clearly. However, in the present apparatus employing the API method, the present invention is an effective means because a very clear TIC can be drawn as compared with other methods (for example, the TSP method and the CFF method). For example, in the case of the CFF method, even if the mass spectrum is displayed when the signal peak of the UV chromatogram becomes the maximum, the mass spectrum required by the measurer cannot be obtained. This is because there is a time lag of about 30 seconds after the sample is detected by the UV detector 13 until the sample is ionized and taken into the data processing device 9. Moreover, TIC cannot be drawn clearly using the background spectrum of glycerol, and it is not possible to determine where the sample from LC1 has been introduced. Therefore, the current method relies on the peak of the UV chromatogram and displays the mass spectrum after 30 seconds, for example, by pressing the space key on the keyboard.

Further, in the case of the TSP method, although the time lag like the CFF method can be ignored, the TIC cannot be drawn clearly due to the background spectrum of the cluster ions. Therefore, even if the TIC and the UV chromatogram are drawn on the same screen as in the present invention, it is not possible to determine where the sample is ionized, and the mass spectrum is displayed by the signal of the UV chromatograph. . Therefore, there is no point in displaying TIC. The present invention is an effective means only for the LC / API mass spectrometer employing the API method.

Further, according to the present invention, for example, when measuring a sample containing a carbon double bond, light absorption does not occur in the UV detector 13, and therefore, the sample may not be detected in the UV detector 13. However, in this case, the detection can be performed by the TIC in some cases, and the defects can be compensated for each other.

Furthermore, as shown in FIG. 4, by displaying the UV chromatogram and the TIC in different colors and displaying them in a superimposed manner, or by displaying the difference between them, it is possible to know the sensitivity of each sample. When actually measuring, in a sample in which only a very small chromatographic peak can be obtained in a UV chromatogram, there is a case where TIC can be measured with very high sensitivity. Of course, the opposite is true. However, in the conventional measurement method, since the UV chromatogram and the TIC are displayed on different monitors, it is difficult to easily obtain the sensitivity difference. According to the present invention, since it is possible to easily obtain the difference in sensitivity, it is possible to determine what kind of molecular structure of the sample has higher sensitivity in the UV chromatogram, and conversely, whether the TIC has higher sensitivity. It becomes possible.

〔The invention's effect〕

As described above, according to the present invention, a desired analysis result can be easily determined, and the accuracy of the analysis is improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an LC / API mass spectrometer, and FIG.
FIG. 3 is a diagram showing an embodiment in which a UV chromatogram signal can be taken into a data processing device. FIG. 3 is a diagram showing an embodiment in which a UV chromatogram, a TIC, and a mass spectrum are displayed on the same screen of the present invention. FIG. 4 shows an embodiment of the present invention in which the UV chromatogram and the TIC are superimposed and displayed, and an embodiment in which the difference between the UV chromatogram and the TIC is displayed. 1 ... liquid chromatogram, 3 ... atomizer, 8 ... mass spectrometer, 9 ... data processing device, 13 ... UV detector, 14 ...
... A / D converter, 15 ... A / D converter.

Continuation of front page (56) References JP-A-60-207049 (JP, A) JP-A-59-100856 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01J 49 / 00-49/48

Claims (9)

(57) [Claims] 1. A mass spectrometer having an ionization section for ionizing a sample and mass-separating and analyzing the ionized sample, wherein: first detection means for detecting a sample concentration of the sample before ionization; A second detection unit for detecting an ion amount of the ionized sample; and an output of the first detection unit corresponding to a plurality of times and an output of the second detection unit corresponding to a plurality of times on the same display medium. A mass spectrometer comprising display means capable of displaying both at the same time. 2. The mass spectrometer according to claim 1, wherein the output corresponding to the plurality of times is a chromatogram. 3. The mass spectrometer according to claim 1, wherein the sample is supplied from a liquid chromatogram. 4. The method according to claim 3, wherein the first detecting means is a UV detecting means, and the second detecting means is a total ion detector, and the UV chromatogram is obtained based on an output of the UV detector. A mass spectrometer characterized by displaying a total ion chromatogram based on an output of a total ion detector. 5. The mass spectrometer according to claim 4, wherein a mass spectrum corresponding to a portion where a peak is generated in a UV chromatogram or a total ion chromatogram is displayed. 6. The mass spectrometer according to claim 4, further comprising a data processing device operable by a measurer, and displaying a mass spectrum based on a signal from the data processing device. 7. The mass spectrometer according to claim 4, wherein the UV chromatogram or the total ion chromatogram is displayed in different colors. 8. The mass spectrometer according to claim 4, wherein the UV chromatogram or the total ion chromatogram is displayed so as to overlap each other. 9. The mass spectrometer according to claim 6, wherein a mass spectrum is automatically displayed based on the UV chromatogram or the total ion chromatogram.