JPS61272650A - Waveform integration type quantitative measurement method in mass spectrometric analysis instrument - Google Patents

Abstract

PURPOSE:To improve the quantative determination accuracy in the stage of a slight signal and to improve the sensitivity of detection by adding the total waveform together with the max. value of the profile data of a mass peak. CONSTITUTION:The intensity of the magnetic field of the mass number to be measured by a data processor 13 of a mass spectrometric analysis instrument is set by a DAC10 and an acceleration power source and an electric field power source 6 are swept in the voltage type of the analyzing system by a DAC9 with the above-mentioned mass number as a center. The mass peak waveform of the mass number is inputted to a preamplifier 8 by such sweeping and the mass peak waveform is sampled by an instruction for starting integration. The profile data thereof is stored into a profile buffer memory 14. The sweeping is repeated and the profile data is added by a memory 14 at every sweeping. The entire waveform is added together with the max. data of the profile data of the mass data, by which the quantitative determination accuracy in the stage of the slight signal is improved and the sensitivity of detection is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a waveform integration type quantitative measurement method in a mass spectrometer that monitors and quantifies the peak intensity of a specific mass.

[Conventional technology]

FIG. 4 is a diagram for explaining the conventional 31M measurement method in a mass spectrometer.

Selected IonMonit (SIM) is a quantitative measurement method in which a mass spectrometer detects a specific mass number and measures the peak intensity while monitoring the peak, and quantifies the concentration of the mixture from the change in peak intensity.
or) There is a measurement method. The conventional 31M measurement method is shown in Figure 4 (
The analysis system power supply is minutely swept with the analysis system voltage waveform V around the mass number (M/Z value) set as shown in a).
As shown in bl, the maximum value of the detected peak waveform P, 1 mi
are stored sequentially as data. Then, the quantitative value of the sample peak that appears with the passage of retention time is
Based on this data, the area value SP-ΣI mi shown in the shaded area in FIG. 4(b) is calculated.

[Problem that the invention seeks to solve]

However, in the conventional SIM measurement method as described above, when the peak signal is weak and the S/N is poor, it is difficult to detect the peak maximum value. In addition, the quantitative value includes a maximum value of 16.0, which is a part of the total amount of ions received by the collector slit, that is, a part of the area of the peak waveform shown in FIG. 4(a). Sensitivity is poor because I only use it.

Furthermore, there were other problems such as the need to calculate the area value S shown in the shaded area in FIG. 4 (bl) after the measurement.

The present invention solves the above-mentioned problems, and aims to provide a waveform integration type quantitative measurement method in a mass spectrometer that can be expected to improve quantitative accuracy even in the case of minute signals.

[Failure to solve the problem]

Therefore, in the waveform integration type quantitative measurement method in the mass spectrometer of the present invention, the waveform in the mass spectrometer performs quantification by micro-sweeping the analysis system power supply around the mass number to be measured and sampling the mass peak waveform received by the collector slit. This is an integration type quantitative measurement method, in which the mass peak waveform in the sweep range is sampled according to the integration instructions, the profile data is integrated, and the area value and profile data of the integrated profile data corresponding to the total amount of ions received by the collector slit are calculated. The method is characterized in that the maximum value of the integrated profile data corresponding to the peak maximum value of the data is determined and quantified.

[Effect]

In the waveform integration type quantitative measurement method in the mass spectrometer of the present invention, profile data are integrated, so the integrated waveform becomes an integrated waveform corresponding to the total amount of ions received by the collector slit. Therefore, the area is determined as the total ion amount, and the maximum value (peak value) is determined as the peak maximum value of the profile data, and by using this value, highly accurate quantification becomes possible.

〔Example〕

Examples will be described below with reference to the drawings.

Fig. 1 is a diagram showing an example of the configuration of a mass spectrometer to which the present invention is applied, Fig. 2 is a diagram illustrating integration of analysis system voltage waveforms, peak waveforms, and profile data, and Fig. 3 is an integrated profile. - It is a diagram for explaining data.

In Figure 1, ■ is an ion source, 2 is an electric field, 3 is a magnetic field,
4 is a collector slit, 5 is an acceleration power source, 6 is an electric field power source, 7 is a magnetic field power source, 8 is a preamplifier, 9 and 10 are DACl
11 is an AD'C, 12 is a display, 13 is a data processing unit (CPU), and 14 is a profile buffer memory. The DACs 9 and 10 convert digital signals into analog signals in accordance with control commands from the data processing device 13 to control the acceleration power source 5, the electric field power source 6, and the magnetic field power source 7. The ADCII converts an analog signal into a digital signal in order to send it to the data processing device 13. The mass peak signal detected by the collector slit 4 is amplified by the preamplifier 8, and the ADCLI converts the analog signal into a digital signal to be sent to the data processing device. 13
sent to. In the data processing device 13, the DACs 9 and 10
to set the magnetic field strength to be measured by controlling the acceleration power supply 5, electric field power supply 6, and magnetic field power supply 7 through the
・Take in the pull file data detected by the collector slit 4 through the preamplifier 8 and ADCII, and store it in the profile buffer memo January 4,
Perform addition processing. Furthermore, in order to obtain the data necessary for quantification, the area value and maximum value of the accumulated pull file data obtained by the addition are determined and displayed on the display 12. The specific processing will be explained below.

■ The data processing device 13 determines the mass number M to be measured.

Set the magnetic field strength of DACIO.

■ Mass number M. The acceleration power source 5 and the electric field power source 6 are minutely swept by the DAC 9 with the analysis system voltage waveform V shown in FIG. With this sweep, the mass number M as shown in FIG. 2 far is obtained. The mass peak waveform PM is input to the preamplifier 8.

(2) In response to an instruction to start integration, the mass peak waveform P is sampled by the ADC II during sweeping, and the flow file data is stored in the profile buffer memory 14.

■ Repeat the sweep further and add the profile data to the profile buffer memo January 4 each time. As a result, profile buffer memory 1
In step 4, when the minute sweep is repeated, the profile .tau.-time is sequentially added for each sweep range to obtain integrated profile data.

■ Stop adding sweep data when instructed to finish integration.
The contents of profile buffer memory 14 are displayed on display 12.

■ Calculate the area value and maximum value from the integrated profile data. That is, the area value Si of the integrated profile data (the area of the shaded part shown in FIG. 3) corresponds to the total amount of ions received by the collector slit 4, and The peak value in the shaded area) P is the area value of the conventional peak maximum value data (
FIG. 4 (area of the shaded part in bl) corresponds to SP.

In addition of the profile data in the above process (■), the analysis system power supply is minutely swept with the analysis system voltage waveform shown in FIG. 2(a), and the profile data (■ and ■') received by the collector slit 4 are As shown in FIG. 2(b), profile data 1 is first stored in the profile buffer memory 14 according to the start and stop of integration.

The next profile data ■' is shown in Figure 2 (C).
It is added on top of the profile data ■ as shown in . In this way, while the integration instruction is issued, the profile data being swept is sequentially sampled and added.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, not only the maximum value of the mass peak profile data as in the conventional method but also all waveforms are added, which improves quantitative accuracy in the case of minute signals. You can expect it. Further, two pieces of information are obtained from the peak waveform after integration, namely, one is the integrated value of the peak maximum value as in the conventional case, and the other is the total area value of the peak waveform integrated data. Furthermore, since the integrated value of the peak maximum value can be accurately indicated from the peak waveform, accuracy is improved and detection sensitivity can be increased compared to the conventional method.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an example of the configuration of a mass spectrometer to which the present invention is applied, Fig. 2 is a diagram illustrating integration of analysis system voltage waveforms, peak waveforms, and profile data, and Fig. 3 is an integrated profile.・A diagram for explaining data. FIG. 4 is a diagram for explaining the conventional SIM measurement method in a mass spectrometer. 1... Ion source, 2... Electric field, 3... Magnetic field, 4...
...Collector slit, 5...Acceleration power supply, 6...
Electric field power supply, 7... Magnetic field power supply, 8... Preamplifier, 9
and 10...DAC. 11...ADC, 12...Display, 13...
- Data processing unit (CPIJ), 14... Profile buffer memory.

Claims (1)

[Claims] This is a waveform integration type quantitative measurement method in a mass spectrometer that performs a minute sweep of the power supply of the analysis system around the mass number to be measured and samples the mass peak waveform received by the collector slit for quantification. The waveform is sampled and the profile data is integrated, and the area value of the integrated profile data corresponding to the total amount of ions received by the collector slit and the maximum value of the integrated profile data corresponding to the peak maximum value of the profile data are calculated. A waveform integration type quantitative measurement method in a mass spectrometer, which is characterized by performing calculation and quantification.