JP2799102B2 - LC / API 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 an LC (L1QUID CHROMATOGRAPH) used for analyzing organic substances and the like.
Y) / API (ATOMOSPHERIC PRESS)
URE Ionization) Ru <br/> relates to a mass spectrometer.

[0002]

2. Description of the Related Art Conventionally, when analyzing organic matter,
It is widely known to atomize components of a sample separated and discharged from liquid chromatography (LC), and then ionize with an API (atmospheric pressure ionization) interface to perform mass spectrometry.

Further, as disclosed in Japanese Patent Application Laid-Open No. 63-248048, an electrode provided between an ionized portion and an intermediate pressure region in an API and an electrode provided between the intermediate pressure region. An API mass spectrometer in which a switching mechanism is provided therebetween so that positive and negative voltages can be applied to enable measurement of positive ions and negative ions, and JP-A-2-446.
As disclosed in Japanese Patent Publication No. 40, an API mass spectrometer capable of measuring positive ions and negative ions by switching the polarity of a needle electrode (electrode for ionization) in synchronization with the polarity switching of the ion acceleration voltage and the drift voltage. A total has been proposed.

[0004]

By the way, the mixture is L
In the case of performing by C / API mass spectrometry, molecules (e.g., a molecule that easily generates a positive ion mass spectrum and a molecule that easily generates a negative ion mass spectrum) may be mixed in components (compounds) that are separated from LC and flow out. Conventionally, no consideration has been given to performing such structural analysis of components with high sensitivity by one mass spectrometry.

That is, the prior art (API)
Although the mass spectrometer has a technique for switching between positive and negative ion measurement modes), these techniques merely switch between positive and negative modes, and the above-described problems when LC and API are combined. Had not pursued.

The present invention has been made in view of the above points, and an object of the present invention is to provide a method for performing LC / API mass spectrometry even if substances producing positive and negative ion mass spectra are mixed.
The sample can be analyzed with a single analysis with high sensitivity,
Another object of the present invention is to provide a mass spectrometer that facilitates structural analysis.

[0007]

The present invention SUMMARY OF], in order to achieve the above object, basically proposes following LC / API mass spectrometer.

[0008] That is, the separation and outflow of the sample from the LC
LC / A for mass spectrometry after ionizing components with API
In the PI mass spectrometer , for each component separated from and out of the LC (here, if there is a substance that coexists with the component, the coexisting substance is also included), the positive ion mass spectrum and the Measurement mode switching means for switching the measurement mode of the negative ion mass spectrum at least once to execute mass spectrometry scanning; and the positive and negative ions
The results of mass spectrometry in the mass spectrum measurement mode
One screen for each component separated and effluent by LC
Mass spectrogram of the negative ion mass spectrum
Depending on the area displayed without distinguishing between positive and negative and the positive and negative attributes
Image area at the same time
And an image display means shown in FIG.

[0009]

[0010]

[0011]

[0012]

According to the above arrangement, the measurement mode of the positive / negative ion mass spectrum is set at least once for each component separated and discharged from the LC within the time required for the flow of the component.
It is executed by mode switching. As a result, a molecule that easily generates a positive ion mass spectrum and a molecule that easily generates a negative ion mass spectrum are detected with high sensitivity to generate respective spectra, and such mass analysis is realized by one sample introduction. .

Furthermore, the results of mass spectrometry are analyzed for each component.
It is possible to display one screen at a time through the display screen,
In this case, one screen shows the positive and negative ion mass spectra.
Of the mass spectrumgram of
And displayed with directions according to the positive and negative attributes
Are divided into regions and displayed simultaneously.

According to such an image display, one screen can be displayed.
For each component, the mass spectrum of the positive and negative mass spectra
And the mass spec
Displaying positive and negative directions (different directions)
What appears. As a result, the characteristics of the components
Indistinguishable mass spectrum and differentiated positive mass spec
Tor and negative mass spectrum in 3 modes
Analysis from the component, so that the characteristics of the components can be
Simplifies structural analysis and increases analysis reliability
become.

[0015]

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG.
FIG. 2 is an overall configuration diagram of an LC / API mass spectrometer according to an example to which the present invention is applied, and FIG. 2 is a measurement time chart of a positive ion mass spectrum and a negative ion mass spectrum in the present embodiment.

In FIG. 1, a sample introduced into an LC (Liquid Chromatography) 1 is separated out of each component together with a solvent and flows out, and an atomizer 2 heated to 200 to 400 ° C.
Into the atomization state and enter the desolvation chamber 3. Desolvation room 3
Is heated to 400 ° C., and these heats are taken as solvent + heat of vaporization of sample 4.

Thereafter, the solvent + sample 4 is exposed to an atmosphere of corona discharge at the voltage of the needle electrode power supply 7 applied to the needle electrode 6 to cause primary ionization of the solvent molecules, and the sample is subsequently ionized by the ion molecule reaction. You.

The generated ions pass through the first pore 17 and the second pore 19 through the vacuum chamber 5 and pass through the electrostatic lens 1.
The light is converged at 0 and sent to the mass spectrometer 18. Mass spectrometer 1
Ion incident on the fan 8 is a sector electric field 11 and a sector magnetic field 12
Through the magnetic field sweep (scan for analysis), and enter the ion detector 13 after mass separation.

The LC / API mass spectrometry in this embodiment is basically performed within the time required for outflow for each component separated from and outflow from LCI (including the coexisting substance, if any). to incorporate both measurement modes ion mass spectrum and the negative ion mass spectra, respectively less <br/> and once each be the positive ion mass spectrum and each measurement mode of the negative ion mass spectra in the outflow time of each component A method of performing scanning by mass spectrometry alternately is adopted. Therefore, the power supply voltage controller 16 controls the needle electrode voltage power supply 7, the drift voltage power supply 8, the ion acceleration voltage power supply 9, the electric field voltage power supply 14, and the magnetic field voltage power supply 15.
Is controlled as shown in FIG.

In FIG. 2, a positive voltage and a negative voltage are periodically generated by synchronizing a needle electrode voltage, a drift voltage, an ion accelerating voltage, an electric field voltage, and a magnetic field sweeping voltage (scanning voltage). When is on the (+) side, it is a measurement mode for obtaining a positive ion mass spectrum, and when it is on the (-) side, it is a measurement mode for obtaining a negative ion mass spectrum. Further, to in FIG. 2 is the outflow time of each component of the sample flowing out of the LC1, during which time the above-mentioned positive voltage and negative voltage are generated alternately, and in addition, the positive and negative scanning (magnetic field) Sweep) is performed.

In this way, even if the components of the sample flowing out of the LC1 contain a substance that easily produces a positive ion mass spectrum and a negative ion mass spectrum, the positive ion mass spectrum and the negative ion mass spectrum can be detected with high sensitivity. It can be measured with a single sample introduction.

FIG. 3 shows various modes of the display method of the measurement result of this embodiment. Note that the display medium may be a printer or the like in addition to a display such as a CRT or a liquid crystal.

FIG. 3 (a) shows the separation and outflow from LC.
For each component, mass spectrograms of a positive ion mass spectrum and a negative ion mass spectrum obtained as a result of the measurement are separately displayed on one screen. Specifically, a positive ion mass spectrum and a negative ion mass spectrum for each component are arranged vertically on one screen so that they can be distinguished. The horizontal axis is the mass number (m / z)
The vertical axis indicates the spectrum value.

FIG. 3B shows an example of a display mode according to the present invention.
In the upper region of one screen, the combined mass spectrum of the positive and negative ion mass spectra for each component is displayed without distinction between positive and negative, and the mass spectrum is displayed in the lower region as positive and negative. This is displayed with a negative distinction (different direction).

According to the embodiment shown in FIG .
And the mass spec of the positive and negative mass spectra for each component.
And the mass spec
Display the torque in positive and negative directions (different directions).
Things appear. As a result, the characteristics of the components
Independent mass spectra and distinct positive mass spectra
Mass spectrum of a total of three modes of
The characteristics of the components can be analyzed from the embodiment shown in FIG.
Even when compared, it is more diversified, so structural analysis
And the analysis reliability can be improved.

[0027] in FIG. 3 (c), positive in the mass spectrogram obtained in the above examples, the Lee Onpiku intensity negative ion mass spectra were summed at each component unit, collectively these added values Indicate by chromatogram (as whole sample). Here, the positive and negative ion peak intensities are separately added, and the positive and negative chromatograms are displayed on a single screen in an upper row and a lower row. The horizontal axis represents time, and the vertical axis represents the total ion current value (TIC).

FIG. 3 (d) is obtained in the same manner as in FIG. 3 (c).
The positive and negative ion mass spectra of each component unit.
The sample formed as a whole without discrimination as positive and negative and the sample formed as discriminating positive and negative are displayed together as a chromatogram of the entire sample on the upper and lower rows of one screen.

According to these, even if the sample is a complex mixture, the structure can be easily and accurately analyzed.

FIG. 3 (e) shows, for each component, positive and negative ion mass spectra (arbitrary ion peak intensities) added without distinction, and this is added as a chromatogram of the entire sample at the top of one screen. In the lower part, one of the components is arbitrarily selected, and is displayed as a mass spectrum gram distinguishing positive and negative.

FIG. 3 (f) shows, in one screen, a chromatogram similar to the upper one in FIG. 3 (e) in the upper part thereof, and one component in the lower part in the lower part. It is arbitrarily selectable and displayed as a mass spectrumgram.

According to FIGS. 3E and 3F, the structural analysis of the entire sample and one component therein can be easily performed through one screen.

Although a fan-shaped magnetic field is used as the mass spectrometer 18 in the above embodiment, a quadruple filter type mass spectrometer may be used. In this case, the output signal is switched so as to generate a signal that is successively proportional to the positive ions and the negative ions, and further in synchronization with the output signal, the LC / A
By switching the drift voltage of the PI and the needle electrode voltage, a positive ion mass spectrum and a negative ion mass spectrum can be measured alternately.

[0034]

According to the present invention , since a positive ion mass spectrum and a negative ion mass spectrum can be measured in one analysis, a substance which easily forms a positive ion and a substance which easily forms a negative ion are mixed. Even for a sample, highly sensitive analysis can be performed while reducing the measurement time.

Further, the mass spectrum gram display or the chromatogram display for each component is diversified in one screen.
Since the ropes easily 且 the structural analysis of the entire components and sample
Can be performed with high reliability .

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an example of an LC / API mass spectrometer to which the present invention is applied.

FIG. 2 is a measurement time chart of a positive ion mass spectrum and a negative ion mass spectrum according to one embodiment of the present invention.

FIG. 3 is an explanatory view showing various aspects of a mass spectrum display used for mass spectrometry of the present invention.

[Explanation of Signs] 1 ... Liquid chromatography (LC), 2 ... Atomizer, 3
... Desolvation chamber, 4 ... Solvent + sample, 5 ... Vacuum chamber, 6
... needle electrode, 7 ... needle electrode power supply, 8 ... drift voltage power supply, 9
... Ion acceleration voltage power supply, 10 ... Electrostatic lens, 11 ... Fan electric field, 12 ... Fan magnetic field, 13 ... Ion detector, 14 ... Electric field voltage power supply, 15 ... Magnetic field voltage power supply, 16 ... Electric field voltage controller, 17 ... First Pores, 18 ... mass spectrometer, 19 ...
Second pore

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01J 49/26-49/32 G01N 27/62 G01N 30/72

Claims (1)

(57) [Claims] 1. An LC / API mass spectrometer for mass spectrometry after ionizing a component of a sample separated and discharged from liquid chromatography (hereinafter abbreviated as LC) with an atmospheric pressure ionization interface (hereinafter abbreviated as API), Measurement of positive ion mass spectrum and negative ion mass spectrum for each component separated from and out of LC (if there is a substance coexisting with the component, including the coexisting substance) within the time required for the component to flow out Mode at least once
Measurement mode switching to perform the scan of the mass spectrometry switching
Means and the quality of the positive and negative ion mass spectra by the measurement mode.
The results of the mass analysis were analyzed for each component separated and effluent by the LC.
Mass spectrum of positive and negative ion mass spectra on the screen
The area where the crotogram is displayed without distinguishing between positive and negative
Divide into areas to display with directionality according to negative attributes
LC / API mass spectrometer, comprising: image display means for displaying images simultaneously .