JPH08287866A - Mass analysis method and device thereof - Google Patents

Abstract

PURPOSE: To provide a high-speed and high-resolution ion trap mass analyzer by controlling an auxiliary voltage, an amplitude factor of a high frequency voltage, and a scan speed of a high frequency voltage amplitude. CONSTITUTION: An ion trap is composed of a ring electrode 6, and two end cap electrodes 7, 8 disposed to face each other having the ring electrode 6 between them. A sample as subject to mass analysis which passes from a sample source 1 through a sample introducing part 2 to be injected to space between the electrodes collides with an electron getting through a center port 12 of the end cap electrode 7 into the space between the electrodes to be ionized. By a main power supply 4 for operation, a quadrupole electric field is generated in the space 15 between the electrodes by a DC voltage U and a high frequency voltage Vcos Ωt supplied into between the end cap electrodes 7, 8 and the ring electrodes 6. For causing resonance of ions as subject to detection to be radiated, a separate voltage from the quadrupole electric field to generate a micro-electric field is applied to between the end cap electrodes 7, 8 by an auxiliary voltage source 11, and a control part 3 adjusts an amplitude ratio between the resonance voltage and the high frequency voltage, and determines mass scan speed to radiate the ions from a detection port 13 in accordance with necessary resolution for each ion as subject to detection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion trap mass spectrometer for analyzing the mass of ions at high speed and with high resolution throughout the entire mass number range of ions.

[0002]

2. Description of the Related Art An ion trap mass spectrometer is shown in FIG.
As shown in 0, it comprises a ring electrode 6 and two upper and lower end caps 7 and 8 arranged in opposite directions so as to sandwich it. An ion generating electron gun 5 is arranged in the central portion above the upper upper end cap 7, and a central port 12 is opened in the central portion of the upper end cap 7 below the ion gun.
On the other hand, a detector 9 is provided in the central portion below the lower end cap 8.
Is provided, and a detection port 13 is opened in the central portion of the lower end cap 8 above it. A DC voltage U and a (main) high frequency voltage 16 (VcosΩt) are applied to each of the electrodes 6, 7 and 8 and the stability of the ion orbit in the quadrupole electric field formed in the inter-electrode space 15 is Size (ring electrode inner diameter r
_o ), the DC voltage U applied to the electrodes, the amplitude V of the high-frequency voltage and its angular frequency Ω, and the a and q values obtained by the valence ratio (m / Z) of the ions to the mass. . The a value and the q value are stable in the ion trap represented by a = 8 eU / (mr _o ² Ω ² ) ... (1) q = 4 eV / (m r _o ² Ω ² ) ... (2) The stable region diagram of FIG. 11 shows the range of the a value and the q value that give the trajectory.
All the ions corresponding to the stable region S stably fly in the inter-electrode space 15. Among them, ions having a specific mass-to-charge ratio are destabilized and emitted, and detected by the detector 9. In this case, as disclosed in JP-A-2-103856, the speed for scanning the mass-to-charge ratio of the detection target ions is usually constant, so that for each ion having each mass-to-charge ratio, A fixed analysis time is assigned to each regardless of the mass-to-charge ratio. Note that the analysis time here is from the time when each ion is destabilized and starts to be emitted until the ion whose mass-to-charge ratio is adjacent to the ion that has started to be destabilized and starts to be emitted. It's time.

In the method of destabilizing the trajectory of a specific ion by generating a weak auxiliary electric field in the inter-electrode space 15 as compared with the quadrupole electric field, usually, during the scanning of the mass-to-charge ratio, An auxiliary AC voltage (V _a cos ωt) 17 having _a constant amplitude is applied regardless of the amplitude of the high frequency voltage 16. The amplitude ratio between the auxiliary AC voltage 17 and the main high frequency voltage 16 is closely related to the resolution. As shown in FIG. 12, the smaller the amplitude ratio is, the higher the resolution is, but the time required for destabilizing the trajectory is increased. . In addition, in the figure, a portion indicated by a symbol IS is an unstable region.

Therefore, in the conventional mass-to-charge ratio scanning method, when it is necessary to analyze ions having a large mass-to-charge ratio with high resolution, the amplitudes of the auxiliary voltage 17 and the main high-frequency voltage 16 are adjusted according to the required resolution. It is necessary to set the ratio small and set the analysis time long enough for the ion orbit to become unstable. In other words, it is necessary to reduce the scanning speed of the mass-to-charge ratio. US Patent Specification No. 51824
No. 51 discloses an ion trap method in which the mass-to-charge ratio scan rate is very slow for high resolution analysis.

[0005]

However, in this method, it takes a very long time to analyze ions in the entire range,
Further, if the ions are trapped in the ion trap for a long time, a position shift (mass shift) of the mass spectrum occurs, which may reduce the analysis accuracy. That is, in the conventional method shown in FIG. 13, a resonance voltage having a constant amplitude is applied throughout the scanning of the mass-to-charge ratio within the range (M _{1 to} M _n ) to be detected, while the high-frequency voltage amplitude changes with time. In contrast, scanning is performed while changing linearly. Therefore, in the conventional method, as the value of the mass-to-charge ratio of the ions to be detected becomes higher, the amplitude ratio between the auxiliary voltage and the high frequency voltage becomes smaller, and the ion having a higher mass-to-charge ratio is detected with higher resolution. However, since the high frequency voltage amplitude is scanned linearly with respect to time, the analysis time for each ion is approximately evenly distributed. Therefore, if a high mass number ion is set to an amplitude ratio between the auxiliary voltage and the high frequency voltage that is small enough to be analyzed with the desired resolution, an analysis time long enough to destabilize the high mass number ion Must be assigned to all ions, increasing the overall analysis time. That is, _a long analysis time is assigned to an ion having a low mass number, which has a small ratio between the auxiliary voltage V _a and the high-frequency voltage V and requires less time for destabilization than a high mass number ion.

As described above, in the above method, since the mass-to-charge ratio of the ions to be detected is scanned at a constant speed, a fixed time is allocated to the analysis of each ion having a different mass-to-charge ratio. . Therefore, if the amplitude ratio between the auxiliary voltage and the main high-frequency voltage is set to a very small value in accordance with an ion having a high mass-to-charge ratio and high resolution, it is very difficult to destabilize the trajectory of the target ion. take time. That is, a certain very long analysis time is assigned to each ion. Further, in the above method, a large amount of time is required for mass analysis of all the ions in the mass range of the detection target, and in particular, the amplitude ratio is set high for ions having a low mass-to-charge ratio, which makes it impossible to detect in a short time. It takes more time than necessary to analyze even the stabilizing ions.

On the other hand, if the ions are confined in the ion trap for an unnecessarily long time, collisions with the neutral gas and interactions with other ions are greatly affected, so that the position of the obtained mass spectrum is reduced. Deviation (mass shift)
Is very large and the accuracy of analysis is likely to deteriorate.

The present invention has been made in view of such circumstances of the prior art, and an object thereof is to perform mass analysis at high speed with a sufficiently high resolution necessary and sufficient throughout the entire mass-to-charge ratio range of ions to be detected. And to provide an ion trap mass spectrometer with high analysis accuracy.

[0009]

In order to achieve the above-mentioned object, the present invention provides an amplitude ratio between an auxiliary voltage and a high frequency voltage according to the necessary resolution of each ion, a mass-to-charge ratio, etc. By performing the operation while changing the analysis time or the scanning speed of the mass-to-charge ratio, the mass analysis to achieve the desired resolution was accelerated.

More specifically, the first means is that at least a high frequency voltage of a direct current voltage and a high frequency voltage is mainly applied between the annular ring electrode and the two end cap electrodes arranged facing each other so as to sandwich the annular ring electrode. In a mass spectrometric method in which ions that are stably captured in a quadrupole electric field created in the interelectrode space by being applied from a power source are emitted from the interelectrode space to detect the mass of the ions, they are applied to the end cap electrodes. The ion is emitted by changing the amplitude ratio between the auxiliary AC voltage for generating the auxiliary AC electric field and the high-frequency voltage according to the resolution required for mass analysis of the ions to be detected.

According to the second means, in the same presumed mass spectrometric method, the mass-to-charge ratio is scanned within the range of the mass-to-charge ratio of the ion to be detected, and the mass-to-charge ratio values are different. Is sequentially detected with time. In this case, the time assigned to the analysis of each ion may be changed according to the mass-to-charge ratio of the detection target ion.

The third means has an annular ring electrode and two end cap electrodes arranged facing each other so as to sandwich the annular ring electrode, and a DC voltage and a high frequency voltage are applied between the ring electrode and the end cap electrode. Of the ions that are stably trapped in the quadrupole electric field created in the interelectrode space by applying at least a high-frequency voltage from the main power supply, the trajectory of the ion with the mass-to-charge ratio to be detected is In a mass spectrometer that destabilizes by generating an auxiliary AC electric field that is weaker than the polar electric field and ejects the ion from the interelectrode space to detect the mass of the ion, it is applied to the end cap electrode to assist. Control means is provided for changing the amplitude ratio between the auxiliary AC voltage for generating an AC electric field and the high-frequency voltage according to the resolution required for mass analysis of ions to be detected. The features.

In this case, even if the control means changes the amplitude ratio in accordance with the value of the mass-to-charge ratio of each ion, the half-width of the mass spectrum of each ion sets the amplitude ratio to a target value. You may change so that it may become.
Further, even if the amplitude ratio between the auxiliary AC voltage and the high frequency voltage is changed so that the required resolution of the ion to be detected becomes higher, the auxiliary AC becomes higher as the value of the mass-to-charge ratio of the ion to be detected becomes higher. It may be changed so that the amplitude ratio of the voltage and the high frequency voltage becomes small. Further, the third means may be provided with means for changing the amplitude of the auxiliary AC voltage so as to always satisfy the ratio of the auxiliary AC voltage and the high frequency voltage obtained from the resolution necessary for analyzing each ion, Further, there may be provided means for scanning with scanning characteristics having different mass-to-charge ratios, depending on which point of the characteristics that determine the stability of the trajectory of the ions oscillating in the space between the ion trap electrodes causes the ions to resonate. .

A fourth means is the same mass spectrometer as the third means, and is provided with means for scanning the mass-to-charge ratio within the range of the mass-to-charge ratio of the ion to be detected. It is characterized in that the respective ions having different values of mass-to-charge ratio are sequentially detected by scanning by means of means.

In this case, it is possible to further provide means for changing the time allotted for the analysis of each ion by the scanning means according to the mass-to-charge ratio of the ions to be detected. At this time, it is essential that the changing means allocates a sufficient time for the ions to be emitted as the analysis time for each ion because the orbit of each ion becomes unstable. Also,
The scanning means may change the scanning speed of the mass-to-charge ratio in accordance with the amplitude ratio of the auxiliary voltage and the high frequency voltage. At this time, the scanning means may be changed such that the scanning speed of the mass-to-charge ratio becomes slower as the amplitude ratio of the auxiliary voltage and the high frequency voltage becomes higher. Further, the scanning means may change the scanning speed of the mass-to-charge ratio according to the mass-to-charge ratio of the detection target ions. At this time, the scanning means may be changed such that the scanning speed of the mass-to-charge ratio becomes slower as the value of the mass-to-charge ratio of the ions to be detected becomes higher.

In the fourth means, the mass-to-charge ratio of the ions to be detected may be set to be scanned by scanning the amplitude of the high frequency voltage. At this time, when the amplitude of the high-frequency voltage changes as represented by a + 1st-order function of the elapsed time of mass analysis of all ions in the detection target range, the range of the mass-to-charge ratio of the detection target is changed. Even if it is divided into at least two regions and is scanned so that the scanning speed of the high-frequency voltage amplitude changes in each region, the amplitude of the high-frequency voltage is at least +1 or less of the elapsed time of mass analysis of all ions in the detection target range. Even if scanning is performed while changing the amplitude as represented by the function of the positive order of, the amplitude of the high frequency voltage is represented by the function of the order of +1/2 of the elapsed time of the mass analysis of all ions in the detection target range. The scanning may be performed by changing the following.

In the fourth means, even if the scanning of the mass-to-charge ratio of the detection target ions is performed by scanning the frequency of the high frequency voltage, the scanning of the mass-to-charge ratio of the detection target ions is performed. The magnitude of the DC voltage may be scanned, or the mass-to-charge ratio of the ions to be detected may be scanned by both the amplitude of the high frequency voltage and the DC voltage.

In addition to the fourth means, the range of the mass-to-charge ratio of the ions to be detected is divided into two or more regions, and the mass-to-charge ratio of the ions to be detected and the high frequency are divided in each region. Means may be provided for scanning with different scanning characteristics with respect to the amplitude ratio of the voltage and the auxiliary voltage.

Further, the third or fourth means may be provided with means for controlling the direction in which the resonance ions are destabilized and emitted.

[0020]

As shown in FIG. 12, the smaller the amplitude ratio between the auxiliary voltage and the high frequency voltage, the higher the resolution, but the longer the time required for destabilizing the ions. Based on this relationship, for each ion, the amplitude of the auxiliary voltage is adjusted so that the amplitude ratio of the auxiliary voltage and the high-frequency voltage corresponds to the required resolution. The scan rate of the high frequency voltage amplitude is controlled so that sufficient analysis time is allowed to stabilize.
Therefore, according to the present invention, since the amplitude ratio between the auxiliary voltage and the high frequency voltage is set according to the required resolution, it is possible to perform analysis that achieves the target resolution throughout the entire mass number range. Further, when the amplitude ratio between the auxiliary voltage and the high frequency voltage set to obtain the target resolution is set for each ion, the destabilization time required for destabilization (necessary for destabilizing each ion Since the analysis time assigned to each ion is set based on the total time), unnecessary analysis time can be saved and the total analysis time can be greatly reduced.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] First, a first embodiment will be described. FIG. 1 shows the schematic configuration of the entire ion trap mass spectrometer according to the first embodiment of the present invention.

As described above, the ion trap includes the ring electrode 6 and the upper and lower end cap electrodes 7 and 8 arranged facing each other so as to sandwich the ring electrode 6, and the sample source 1
The sample is supplied to the inter-electrode space 15 via the sample introduction part 2. The ring electrode 6 has a main power supply 4 for operation.
Is supplied from the auxiliary AC voltage power supply 11 to the end cap electrodes 7 and 8. The supply of these power supplies 4 and 11 is controlled by the control unit 3. In addition to these power supplies 4 and 11, the control unit 3 includes an ion generating electron gun 5 arranged in the upper center of the upper end cap electrode 7, a detector 9 arranged in the lower center of the lower end cap electrode 8, And controlling the sample source 1. A data processing unit 10 that processes the detection data detected by the detector 9
Is further provided.

Generally, in the ion trap constructed as described above, the sample to be mass-analyzed, which is injected from the sample source 1 through the sample introduction part 2 into the interelectrode space 15, is terminated by the electron gun 5 for ion generation. It collides with the electrons that have entered the inter-electrode space through the central opening 12 of the cap electrode 7 and is ionized. The main power supply 4 for operation, the end cap electrode 7
And 8 and the ring electrode 6 are supplied with a DC voltage U and a high-frequency voltage Vcos Ωt, the orbits of ions having a mass-to-charge ratio (m / Z) flying in a quadrupole electric field generated in the interelectrode space 15 are stable. Whether it is unstable or not depends on which a or q point of the stable region S or the unstable region IS shown in FIG. The stable state refers to a state where the vibration amplitude does not exceed a certain value and is vibrating in the inter-electrode space, and the unstable state refers to a state where the vibration amplitude increases and is emitted from the electrode space. Note that a and q are represented by the equations (1) and (2) as described above.

The voltage applied to the electrodes by the main operating power supply 4 based on the range of the mass of the ions to be mass analyzed (mass-to-charge ratio m / Z) depends on the size of the ion trap and the frequency of the high frequency voltage. It is determined by the control unit 3. In this embodiment, as the operating voltage, only the high frequency voltage is applied without applying the DC voltage. At this time, in the stable region diagram of FIG. 11, it corresponds to a straight line of a = 0, and a = 0 in the stable region S
All the ions corresponding to the straight line of are stably trapped. At this time, as is apparent from the equations (1) and (2), it is utilized that the value of q is different when the mass number (mass-to-charge ratio m / Z) of the ion is different, and 0 ≦ q ≦ 0. 908 (3) In the range of (3), an auxiliary voltage that resonates only ions of a mass number corresponding to a value of q (resonance emission point) is applied to cause resonance emission to perform mass separation.

Once all the ions in the target mass number range have been trapped, the amplitude of the high frequency voltage is gradually increased.
The mass number (mass-to-charge ratio m / Z) of ions corresponding to a certain q point (resonance emission point) inside the stable region increases. Therefore, the orbit gradually becomes unstable from an ion with a small mass number to an ion with a large mass number, and the ions are transmitted through the central port 12 and the detection port 13.
Only the ions emitted through the interelectrode space 15 through the detection electrode 13 and emitted from the interelectrode space 15 through the detection port 13 are detected by the detector 9 and processed by the data processing unit 10.
That is, scanning is performed so that the amplitude of the high-frequency voltage is gradually increased, and mass separation is performed sequentially from ions having a small mass-to-charge ratio to ions having a large mass-to-charge ratio. At this time, the control unit 3
Then, a series of mass separation processes-ionization of sample, adjustment of amplitude ratio between resonance voltage and high frequency voltage, mass scanning, detection,
Data processing-controls the whole. The resonance emission will be described below.

In the resonance emission, the mass number (mass-to-charge ratio (m / Z)) of ions that resonate with the auxiliary electric field generated by the auxiliary AC voltage applied to the end cap electrodes 7 and 8 by the auxiliary AC voltage power supply 11 is determined. Therefore, it is possible to destabilize and emit ions of a specific mass. Needless to say, the auxiliary electric field is weaker than the quadrupole electric field due to the nature of the ion trap. The amplitude of is closely related to the resolution of the mass spectrum due to resonance emission, and the time required until each ion is destabilized and emitted (hereinafter referred to as “destabilization time”). The numerical analysis result of the above relationship when a = 0 and q = 0.404 in FIG. 11 is shown in FIG.
This figure shows the amplitude ratio of the superposed voltage and the high frequency voltage (V _a / V)
The relationship between instability time [ms] and resolution (M / ΔM) for × 100 [%] is shown. Based on this relationship, it is possible to determine the magnitude of the amplitude ratio between the auxiliary voltage and the high frequency voltage required to achieve the required resolution, and the minimum required analysis time. For example, the resonance point is a
= 0, q = 0.404, when analyzing ions requiring a resolution of about 300, the auxiliary voltage amplitude is set so that the amplitude ratio between the high frequency voltage and the auxiliary voltage is 0.02%, Further, it can be seen that the analysis time needs to be set to 1.5 ms or more.

Based on the relationship shown in FIG. 12, the required resolution M / ΔM for each ion within a certain mass range is calculated so that the half-value width ΔM of each mass spectrum is ΔM = 0.5. If it is set to 0.0 × M, the required resolution changes depending on each mass-to-charge ratio of ions. FIG. 2 shows an example of a method of scanning the high frequency voltage amplitude and the amplitude ratio of the auxiliary voltage and the high frequency voltage according to each resolution.

In the method of this embodiment shown in FIG. 2, the method shown in FIG.
Unlike the conventional method shown in FIG. 3, while applying a resonance voltage having a substantially constant amplitude as in the conventional method, the high frequency voltage amplitude is + 1/1 / the analysis elapsed time t as shown in equation (4).
As shown by a quadratic function, in other words, scanning is performed so as to be proportional to the 1/2 power.

V = C ₁ (t + C ₂ ) ^1/2 + C ₃ (4) [C ₁ , C ₂ and C ₃ are constants] However, in this case, the range of the mass-to-charge ratio of the analysis target is maintained. To scan. For example, in proportion to the range (V ₁ ~V _n) in a mass-to-charge ratio of the high frequency voltage amplitude corresponding to a range of mass-to-charge ratio to be detected _{(M 1 ~M n) (4} ) scanning according formula To do. As a result, the higher the mass-to-charge ratio of the ions to be analyzed, the lower the amplitude ratio between the auxiliary voltage and the high frequency voltage, and the higher resolution the analysis. In addition,
Figure 2 is a high-frequency voltage amplitude V = f (t ^1/2), in case when the auxiliary voltage amplitude was set to V = c ₃ a c ₃ is a constant, V ₁
Corresponds to the mass-to-charge ratio M ₁ and V _n is the mass-to-charge ratio M _n
It corresponds to. The analysis time T _i assigned to the i-th ion is proportional to M _i .

In the method of this embodiment, based on the characteristics shown in FIG. 12, a sufficient and sufficient time for destabilizing the ions analyzed at each required resolution is allocated, and an extra analysis time is eliminated. To scan the mass-to-charge ratio. In other words, if the mass-to-charge ratio scan is performed based on the characteristics of FIG. 12, the target resolution can be achieved for ions with sufficient low resolution analysis while analyzing ions within the target mass number range. By setting a large amplitude ratio between the auxiliary voltage and the high-frequency voltage within the range, destabilizing it faster and setting the assigned analysis time shorter, the analysis time in the entire mass number range can be greatly shortened. .

Next, the shortening time of the analysis time when using this embodiment will be concretely obtained. Now, the range of the mass-to-charge ratio to be detected is set to M _{1 to} M _n, and the allotted time required for destabilizing the ion having the maximum mass-to-charge ratio M _n within the detection range is ΣΔt _i (however, 1≤i≤n; the same applies hereinafter), the total analysis time T by the conventional method
₀ is the time assigned to mass spectrometry for ions of each mass-number charge ratio is constant at Δt over the entire mass range, therefore T ₀ = {M _n − (M ₁ −1)} × Δt = ( M _n −M ₁ +1) × Δt (5)

On the other hand, if the resonance emission points (q values) are the same, the destabilizing time Δt of the M _i ion is determined by the characteristics shown in FIG.
_It was found that _i is Δt _i = (Δt / M _n ) M _i (6) [Δt is the time required for analysis of M _n ]. Therefore, since the analysis time of each ion is the minimum required for the destabilization time of each ion, in this example, the shortest analysis time of all ions is the sum of the destabilization time of each ion. Become. Therefore, the total analysis time T is as follows: T = ΣΔt _i = (Δt / M ₁ ) ΣM _i = (Δ / M _n ) (1/2) {M _n (M _n +1) − (M ₁ −1) M ₁ }. Is expressed by (7), and the reduced amount is ΔT = T ₀ −T, and from the equations (5) and (7), ΔT = (Δt / 2M _n ) {2M _n (M _n −M ₁ +1) _{) -M n (M n +1)} + (M 1 -1) M 1} = (Δt / 2M n) {2M n 2 -2M 1 M n + 2M n -M n 2 -M n + M 1 2 -M 1 _{} = (Δt / 2M n)} {M n 2 + M n -2M 1 M n + M 1 2 -M 1} = (Δt / 2M n) {(M n -M 1) 2 + (M n -M 1) } = (Δt / 2M _n ) (M _n −M ₁ ) (M _n −M ₁ +1) (8) Usually, since M ₁ << M _N , it can be seen from this equation (8) that the total analysis time in this example is approximately half that of the conventional example.

The mass spectrum obtained at this time, as shown in FIG. 3, has a half-value width of ΔM = 0.5 throughout the entire range regardless of the magnitude of the mass-to-charge ratio. It is a resolution that can be sufficiently identified. Here, when the half-value width of the mass spectrum is set to a value other than 0.5, C _1, C _2, C in the equation (1) is set so as to correspond to it.
By resetting the coefficient of ₃ , it is possible to obtain the mass spectrum of the desired half width.

From the equation (8), the time t at which an arbitrary m ion is mass analyzed is t = (Δt / 2M _n ) {m (m + 1) -M ₁ (M ₁ -1)}, which is a constant. Using B and C, t = Bm (m + 1) -C (9) can be written.

On the other hand, from the equation (2), if the resonance emission point is found, it can be transformed into V = qmr _o ² Ω ² / 4e (10), and A = qr _o ² Ω ² / where A is a constant. Putting 4e, the equation (10) becomes V = A · m (11), and m becomes m = V / A (12). Then, when m is substituted into the equation (9), t = B (V / A) (V / A + 1) −C = (B / A ² ) V (V + A) −C (13) Therefore, from (B / A ² ) V ² + (B / A) V−C + t = 0, ∴V ² + AV− (A ² / B) (t + C) = 0 (14), which is V Solving for: V = (1/2) [− A + √ {A ² + (t + C) 4A ² / B}] = (A / 2) [− 1 + √ {1 + 4 (t + C) / B}] = (A / 2) [√ {(4 / B) t + (4 / B) C + 1} -1] = (A / 2) (2 / √B) [√ {t + C + (B / 4)}-√B / 2] = (A / √B) √ {t + C + (B / 4)}-A / 2 (15) Here, if it is replaced with C ₁ = A / √B C ₂ = C + (B / 4) C ₃ = −A / 2, the above formula (4) is derived.

As described above, according to the first embodiment, it is possible to perform the mass analysis with the target resolution achieved in about half the time of the conventional method. In addition, if the total analysis is performed for a very long time, the ions will be greatly affected by the interaction with the neutral gas and other ions existing in the electrode space, and the position of the mass spectrum will be greatly displaced. It is known to come (mass shift). Therefore, if the total analysis time is shortened, it can be expected that the accuracy of the mass analysis result is prevented from being lowered.

[Second Embodiment] A second embodiment of the present invention will be described with reference to FIG. Note that this embodiment is different from the above-described first embodiment in that the range of the mass-to-charge ratio of the ions to be detected is divided into a plurality of regions for scanning, and other parts that are not particularly described are the first embodiment. Since the configuration is the same as that of the example, the same reference numerals are given to the same components, and duplicate description will be omitted.

In this embodiment, the range of the mass-to-charge ratio of the ions to be detected is divided into a plurality of regions, and each region (16)
As shown by the equation, V = D ₁ t + D ₂ [D ₁ and D ₂ are constants] ... (16) The linear equation is used for scanning. That is, when scanning the high frequency voltage amplitude at a constant speed, the scanning speed (D ₁ value) is changed to analyze the ion mass in the range of the detection target, which is the method of this embodiment. In FIG. 4, the range of the total mass-to-charge ratio is divided into three regions A, B, and C, and the high-frequency voltage amplitude is changed at a constant velocity by changing the velocity (slope) in each region. The scanning speed of the high-frequency voltage amplitude is made smaller (the slope becomes gentler) in a region where the mass-to-charge ratio is higher. In the case of FIG. 4, since the average value of the mass-to-charge ratio increases in the order of regions A, B, and C, the scanning speed decreases in this order.

Therefore, in FIG. 4, the constant D ₁ in the equation (16) is changed to c _1, c _2, c ₃ (c
_1> c _2> c ₃₎ is set and so, the constant D ₂ d _1,
If we take d _{2 and} d ₃ , then in region A, V = c ₁ t + d
₁ , V = c ₂ t + d _{2 in} the region B, V = c ₃ t + in the region B
It becomes d ₃ . The auxiliary voltage amplitude V _{a is, e 1, e 2, e} 3
Is a constant, and V _a = e _1, V _a = depending on the regions A, B, and C.
e _2, V _a = e ₃ .

According to this embodiment, since the scanning speed of the high frequency voltage amplitude is changed according to the level of the magnitude of the mass-to-charge ratio in each region, the analysis time for each ion changes in each region, and Analysis time can be shortened. Further, in this embodiment, since the high-frequency voltage amplitude is scanned at a constant speed, the conventional technique can be applied, and the high-frequency voltage can be scanned more easily than in the first embodiment. Here, the magnitude of the amplitude of the auxiliary voltage can be changed in each region as long as the amplitude ratio of the auxiliary voltage and the high frequency voltage is within the range where the required resolution can be obtained. However,
In each region, D in the equation (16) is obtained so that a time longer than a necessary destabilizing time in the amplitude ratio between the auxiliary voltage and the high frequency voltage, which is obtained from the characteristics of FIG. 12, is assigned to the analysis of each ion. Control unit 3 to determine ₁ and D ₂ values
Control with.

[Third Embodiment] A third embodiment of the present invention will be described with reference to FIG. Note that this embodiment is the same as the above-described second embodiment in that the range of the mass-to-charge ratio of the ions to be detected is divided into a plurality of regions and scanning is performed.
This is an example in which each area is scanned by a scanning method different from that of the embodiment. Also in this embodiment, each part not particularly explained is the first
Also, since the second embodiment has the same configuration as that of the second embodiment, the same reference numerals are given to the same components, and duplicate description will be omitted.

That is, in this embodiment, a region requiring a particularly high resolution is divided within the range of the mass-to-charge ratio of the ions to be detected, and the scanning speed of the high frequency voltage amplitude is reduced only for that region. Mass spectrometry. For example, when an ion containing an atom having an isotope is subjected to mass analysis with an isotope, the half-width ΔM of the mass spectrum is ΔM.
A very high resolution of << 0.5 is required. Therefore, in such a region where high resolution analysis is required, the amplitude ratio between the auxiliary voltage and the high frequency voltage is made extremely small, and the analysis time for allocating each ion is made very long accordingly. . That is, it is necessary to make the scanning speed of the high frequency voltage amplitude very small. At this time, since the amplitude of the high frequency voltage corresponds to the mass number of ions,
Usually, in order not to change the scanning range of the amplitude of the high frequency voltage, the amplitude ratio of the auxiliary voltage and the high frequency voltage is reduced by decreasing the amplitude of the auxiliary voltage.

FIG. 5 shows an example of a specific scanning method of this embodiment.
Shown in If region B of regions A, B, and C in FIG. 5 requires high-resolution analysis, an auxiliary voltage with a constant amplitude, which is much smaller than other regions, is applied to this region,
Meanwhile, the high frequency voltage amplitude is scanned very slowly.
On the other hand, the regions A and C for which the resolution is sufficient so that the full width at half maximum ΔM of the mass spectrum is ΔM = 0.5 are scanned by the same method as in the first embodiment. The conceptual diagram of the mass spectrum obtained at this time is shown in FIG. A mass spectrum having a resolution such that the full width at half maximum ΔM of the mass spectrum of the ion corresponding to the region B is ΔM << 0.5 and the full width at half maximum ΔM is ΔM = 0.5 is obtained in the other regions. Specifically, FIG.
As is also shown, the high frequency voltage amplitude is V = f in the regions A and C.
(T ^1/2), in the region B V = g (t ^1/2) [provided that df
(T) / dt> dg (t) / dt],
The auxiliary voltage amplitude V _a is V _a = e ₁ in the areas A and C, and V _b = e ₂ in the area B [where e ₁ and e ₂ are constants, e ₁ > e ₂ ].
Is set like. Therefore, according to the present embodiment, even if there is a region requiring high resolution analysis in the middle portion within the range of the mass-to-charge ratio of the ions to be detected, the range of the mass-to-charge ratio depends on the required resolution level. Split
By adjusting the amplitude of the auxiliary voltage in each region, it is possible to perform mass analysis at high speed with the desired resolution.

[Fourth Embodiment] A fourth embodiment of the present invention will be described with reference to FIG.

In this embodiment, as shown in FIG. 7, the mass-to-charge ratio range of the ions to be detected is divided into a plurality of ranges, and for the region A corresponding to the low mass number ions, the formula (16) is used. In the region B corresponding to the high mass number ions, the high frequency voltage amplitude is linearly changed with respect to the analysis elapsed time t.
This is an example in which scanning is performed so as to be a function of the ½ order of. Other parts that are not particularly described are configured in the same manner as in the first and second embodiments, and therefore, equivalent parts are designated by the same reference numerals, and redundant description will be omitted.

Specifically, the high frequency voltage amplitude is in the regions A and B.
In the area A, V = c ₁ t + d ₁ , and in the area B, V = f
(T ^1/2 ), the auxiliary voltage amplitude is V _a =
In e ₁ and area B, V _a = e ₂ (where e ₁ and e ₂ are constants).

According to this embodiment, since the high-frequency voltage amplitude is changed at a constant speed in the region of low mass number ions, the analysis time of a certain length is equally distributed and adjacent ions are sufficiently separated. You can As described above, the scanning method of the high-frequency voltage amplitude can be changed for each region according to the mass-to-charge ratio of the detection target, and the optimum mass separation can be performed for each region.

[Fifth Embodiment] A fifth embodiment of the present invention will be described with reference to FIG.

The present embodiment is characterized in that the scanning method of the high frequency voltage amplitude is changed according to the value of q in the stable region diagram of FIG. 11, and the other parts are constructed in the same manner as in the first embodiment. ing. FIG. 12 shows a = in the stable region diagram.
There was a relationship between the amplitude ratio of the auxiliary voltage and the high frequency voltage, the resolution, and the destabilizing time when the point of 0 and q = 0.404 was set as the resonance point. The optimum value of the constants of C ₁ , C ₂ and C _{3 in} the equation (4) representing the method of scanning the amplitude of the high frequency voltage based on this relationship varies depending on the value of q. From more detailed numerical analysis, the amplitude V _a of the amplitude ratio V _a / V and auxiliary voltage of the auxiliary voltage and the high-frequency voltage is _{approximately, V a / Vαq / R ···} (17) V a αq 2 It is known that there is a relationship such as / R [R is resolution] (18). Therefore (4)
The constants such as C ₁ , C ₂ , C _{3 in} the formula and D ₁ , D ₂ in the formula (16) are reset by the resonance point, that is, the value of q, so that more accurate and optimum high speed High resolution mass spectrometry becomes possible. That is, the larger the q, the wider the interval between adjacent ions and the higher the resolution. Therefore, the optimum value of q is selected according to the target ion, and efficient detection is performed in consideration of detection accuracy and detection time. It can be performed.

[Sixth Embodiment] A sixth embodiment of the present invention will be described with reference to FIG.

In the first embodiment, only the high frequency voltage is applied as the operating voltage, but both the DC voltage and the high frequency voltage may be applied. At this time, the scanning method of the mass-to-charge ratio is at least a = x ₁ · q + x ₂ (19) a = x ₃ (20) [x ₁ , x ₂ , x ₃ are constants. ) There are two scanning methods along the straight line. According to the former scanning method, both the DC voltage and the high frequency voltage amplitude are scanned as shown by the straight line c in the figure, but the narrow stable region S above the straight line c is used to stabilize in the ion trap. Since the effect of space charge can be reduced by reducing the number of ions trapped in, it is effective in performing more accurate mass spectrometry. Further, by changing the inclination of the straight line c, the overlapping area with the stable area can be arbitrarily set, so that it is possible to perform analysis as needed. Furthermore, if the amplitude of the high-frequency voltage is very large when scanned, and the amplitude is extremely dangerous, the latter scanning method can be used. It will be possible. Other parts, which are not particularly described, are configured in the same manner as in the first embodiment.

[Seventh Embodiment] A seventh embodiment of the present invention will be described with reference to FIG.

In the present embodiment, in addition to the control unit 3 which can change the scanning method of the mass-to-charge ratio according to the required resolution of the ions to be detected, it is also possible to control the unstable direction of the ions emitted in resonance. It is characterized by having a voltage power supply unit 14. That is, in place of the auxiliary AC voltage power supply in the first embodiment of FIG. 1, a specific direction emission auxiliary AC voltage power supply is provided, and other parts not particularly described are configured in the same manner as in the first embodiment. There is.

Although ions may be destabilized in both directions of the two end caps 7 and 8, in an ion trap mass spectrometer, a detector 9 is usually provided on one side of the end cap as shown in FIG. It is installed only in the direction (the lower end cap electrode 8 side in this embodiment). Therefore, in order to destabilize the destabilizing ions only in the direction of the end cap 8 in which the detector 9 is present, the one-side (specific direction) emission auxiliary voltage power supply unit 14 directs the end cap electrode only in one direction. An auxiliary voltage that does not generate an auxiliary electric field (a minute electric field generated by the auxiliary voltage) is applied.
As a result, the ions are more likely to be destabilized toward the detector 9, so that the detection efficiency is improved. According to this embodiment, high-sensitivity, high-speed, high-resolution mass analysis is possible.

[Eighth Embodiment] An eighth embodiment of the present invention will be described with reference to FIG.

The present embodiment is characterized in that the mass-to-charge ratio scanning method of the ions corresponding to detection is performed by changing the frequency of the high frequency voltage.

At this time, when the amplitude ratio between the auxiliary voltage and the high frequency voltage is changed according to the change in the required resolution, the amplitude of the high frequency voltage is constant as represented by V = V ₀ (const), and therefore the superposition is performed. The amplitude of the auxiliary voltage is changed in synchronization with the mass-to-charge ratio scanning. For example, when mass scanning is performed based on a function of the analysis elapsed time t to the power of 1/2, the amplitude V _{a of the} auxiliary voltage is V _a = E ₁ (t + E ₂ ) ^−1/2 + E _{3 as shown in FIG.} (21) Scan as represented by a function of the analysis time t of [E 1, E 2, E 3 is a constant].

Therefore, according to this embodiment, even when mass scanning is performed by changing the frequency of the high-frequency voltage, the amplitude V _{a of the} auxiliary voltage is changed according to the required resolution, so that high-speed and high-resolution mass analysis can be performed. Is possible. However,
Dividing the mass scan range into a plurality of regions, when the mass scan based on a linear function of the different analyzes elapsed time t of slope for each of the areas, the amplitude V _a of the auxiliary voltage is different analytical elapsed time t of coefficients Scan V _a as represented by the −1 st order function. Other parts, which are not particularly described, are configured in the same manner as in the first embodiment.

[0060]

As described above, according to the present invention,
For each ion, adjust the auxiliary voltage amplitude so that the amplitude ratio between the auxiliary voltage and the high-frequency voltage is adjusted according to the required resolution, and the auxiliary voltage of the above magnitude is sufficient to destabilize each ion. By controlling the scanning speed of the high-frequency voltage amplitude so that various analysis times can be allocated, mass analysis that achieves the target resolution over the entire mass number range can be achieved in a time significantly shorter than in the past.

That is, the amplitude ratio between the auxiliary AC voltage applied to the end cap electrode to generate the auxiliary AC electric field and the high-frequency voltage is changed according to the resolution required for the mass analysis of the ions to be detected, and the ions are emitted. According to the invention of Item 1, the detection target is obtained by changing the amplitude ratio between the auxiliary AC voltage and the high frequency voltage according to the required resolution.
Ions with one mass number can be arbitrarily selected and ejected, and as a result, mass analysis can be achieved with a target resolution throughout the entire mass number range.

The invention according to claim 2, wherein the mass-to-charge ratio is scanned within the range of the mass-to-charge ratio of the ions to be detected, and the respective ions having different values of the mass-to-charge ratio are sequentially detected with time. Therefore, it is possible to sequentially detect ions with a mass number within a certain range by scanning the mass-to-charge ratio, and as a result, it is possible to achieve continuous mass analysis with a target resolution throughout the entire mass number range. Become.

The time allotted to the analysis of each ion is changed according to the mass-to-charge ratio of the ion to be detected.
According to the described invention, it is possible to set the necessary minimum time necessary for analysis in correspondence with the mass-to-charge ratio of the ions to be detected, and as a result, it is possible to avoid wasting detection time in a short time. Can be detected.

A control means for changing the amplitude ratio between the high-frequency voltage and the auxiliary alternating voltage applied to the end cap electrode to generate the auxiliary alternating electric field in accordance with the resolution required for mass analysis of the ions to be detected. According to the invention described in 4, it is possible to provide a mass spectrometer having the same effect as that of the invention described in claim 1.

According to the invention of claim 5, the control means changes the amplitude ratio according to the value of the mass-to-charge ratio of each ion. By setting the amplitude ratio, it is possible to accurately detect in a short time.

According to a sixth aspect of the present invention, the control means changes the amplitude ratio so that the full width at half maximum of the mass spectrum of each ion becomes a target value. Therefore, detection can be performed with high resolution.

According to the invention of claim 7, the control means changes so that the amplitude ratio of the auxiliary AC voltage and the high frequency voltage becomes smaller as the required resolution of the ions to be detected becomes higher. Therefore, the amplitude ratio is reduced to improve the detection accuracy, which enables detection with high resolution.

According to the invention of claim 8, the control means changes the mass-to-charge ratio of the ions to be detected so that the amplitude ratio of the auxiliary AC voltage and the high frequency voltage becomes smaller as the value of the mass-to-charge ratio becomes higher. Since the ratio and the amplitude ratio are correlated with each other, the higher the value of the mass-to-charge ratio, the smaller the amplitude ratio, which enables highly accurate detection.

10. The invention according to claim 9, further comprising means for changing the amplitude of the auxiliary AC voltage so as to always satisfy the ratio of the auxiliary AC voltage and the high frequency voltage obtained from the resolution required for analyzing each ion. In this case, the required resolution is always ensured, which enables highly accurate detection.

A means for scanning with scanning characteristics of different mass-to-charge ratios is provided, depending on which point of the characteristics that determines the stability of the trajectory of the ions oscillating in the space between the ion trap electrodes resonates the ions. According to the invention of Item 10,
Since the scanning characteristics are changed in consideration of the resolution and the detection time according to the characteristics, efficient detection can be performed.

A means for scanning the mass-to-charge ratio within the range of the mass-to-charge ratio of the ion to be detected is provided, and each of the ions having different values of the mass-to-charge ratio is scanned by the means to change with time. According to the eleventh aspect of the invention in which detection is performed sequentially, it is possible to provide a mass spectrometer having the same effect as that of the second aspect of the invention.

According to the invention of claim 12, further comprising means for changing the time allotted to the analysis of each ion by the scanning means in accordance with the mass-to-charge ratio of the ion to be detected. Since the time required for analysis is set according to the charge-to-charge ratio, highly accurate detection can be performed in the minimum necessary time.

According to the invention of claim 13, the changing means assigns a sufficient time for emission of each ion as an analysis time of each ion because the orbit of each ion becomes unstable. Can be detected.

According to the invention of claim 14, the scanning means changes the scanning speed of the mass-to-charge ratio in accordance with the amplitude ratio of the auxiliary voltage and the high frequency voltage. By scanning at low speed and at a high speed in a region that may be detected with low resolution, mass analysis can be performed at high speed with necessary and sufficiently high resolution throughout the entire range of the mass-to-charge ratio of the ions to be detected.

According to the invention as set forth in claim 15, wherein the scanning means changes so that the scanning speed of the mass-to-charge ratio becomes slower as the amplitude ratio of the auxiliary voltage and the high frequency voltage becomes higher. As a result, the analysis time can be shortened, and as a result, the analysis time in the entire mass range can be shortened.

According to the invention of claim 16, the scanning means changes the scanning speed of the mass-to-charge ratio in accordance with the mass-to-charge ratio of the ions to be detected. Since the speed required for analysis is set by
Highly accurate detection becomes possible in the minimum necessary time corresponding to the speed.

According to the present invention, the scanning speed is changed so that the scanning speed of the mass-to-charge ratio becomes slower as the value of the mass-to-charge ratio of the ions to be detected becomes higher. By doing so, the time required to destabilize the ions can be shortened, and as a result, the analysis time in the entire mass range can be shortened.

According to the invention of claim 18, the scanning means scans the mass-to-charge ratio of the ions to be detected by scanning the amplitude of the high frequency voltage. Since the charge ratio scanning can be performed, the scanning becomes simple.

When the scanning means changes so that the amplitude of the high-frequency voltage changes as represented by a + 1st-order function of the elapsed time of mass analysis of all ions in the detection target range, the mass-to-charge ratio of the detection target is changed. 20. According to the invention of claim 19, wherein the range is divided into at least two regions and the scanning is performed so that the scanning speed of the high frequency voltage amplitude changes in each region, the analysis time per ion changes in each region, resulting in Therefore, the total analysis time can be shortened. Further, since the high frequency voltage amplitude is scanned by a linear function (constant speed), the high frequency voltage can be easily scanned.

20. The scanning means changes the amplitude of the high-frequency voltage so that the amplitude of the high-frequency voltage is changed so as to be represented by a function of a positive order of at least +1 or less of the elapsed time of mass analysis of all ions in the detection target range. According to the described invention, the higher the mass-to-charge ratio of the ions to be analyzed, the lower the amplitude ratio between the auxiliary voltage and the high frequency voltage, and the higher resolution the analysis is made. At that time, the detection characteristic can be arbitrarily set by appropriately setting a function of a positive order of +1 or less.

When the amplitude of the high-frequency voltage is equal to the elapsed time of mass analysis of all ions in the detection target range,
22. According to the invention of claim 21, the scanning is performed while changing the scanning as represented by a function of the 1/2 order, and the higher the mass-to-charge ratio of the ions to be analyzed, the higher the auxiliary voltage. The amplitude ratio with the high frequency voltage becomes low, and high resolution analysis is performed.

According to the invention of claim 22, the scanning means performs the scanning of the mass-to-charge ratio of the ions to be detected by scanning the frequency of the high frequency voltage because the amplitude of the high frequency voltage is constant. The high-speed, high-resolution analysis can be performed by changing the amplitude of the superimposed auxiliary voltage in synchronization with the scan of the mass-to-charge ratio according to the required resolution.

According to the invention of claim 23, the scanning means scans the mass-to-charge ratio of the ions to be detected by scanning the magnitude of the DC voltage. When the amplitude becomes extremely large and is dangerous, it is possible to perform scanning with excellent safety by scanning the magnitude of the DC voltage instead of scanning the high frequency voltage.

According to the invention of claim 24, the scanning means scans the mass-to-charge ratio of the ions to be detected by scanning both the amplitude of the high frequency voltage and the DC voltage. It is possible to arbitrarily set the overlapping area with the stable area of, and it is possible to perform accurate analysis in a narrow range as needed.

The range of the mass-to-charge ratio of the ions to be detected is divided into two or more regions, and the mass-to-charge ratio of the ions to be detected and the amplitude ratio of the high frequency voltage and the auxiliary voltage in each region are defined as follows. According to the invention as claimed in claim 25, which comprises means for scanning with different scanning characteristics, the scanning is performed with an appropriate scanning characteristic for each region, so that for each region according to the mass-to-charge ratio of the ions to be detected. Optimal mass spectrometry can be performed.

According to a twenty-sixth aspect of the present invention, which comprises means for controlling the direction in which the resonance ions are destabilized and emitted.
Since it is possible to make the detector unstable in a certain direction, it is possible to control the emission of ions to the detector side and improve the detection efficiency.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of an ion trap mass spectrometer according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a method of scanning a high frequency voltage and an auxiliary voltage in the mass spectrometer according to the first embodiment of the present invention.

FIG. 3 is a conceptual diagram of a mass spectrum obtained when the mass spectrometer according to the first embodiment of the present invention is operated.

FIG. 4 is an explanatory diagram showing a method of scanning a high frequency voltage and an auxiliary voltage in the mass spectrometer according to the second embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a method of scanning a high frequency voltage and an auxiliary voltage in the mass spectrometer according to the third embodiment of the present invention.

FIG. 6 is a conceptual diagram of a mass spectrum obtained when the mass spectrometer according to the third embodiment of the present invention is operated.

FIG. 7 is an explanatory diagram showing a method of scanning a high frequency voltage and an auxiliary voltage in the mass spectrometer according to the fourth embodiment of the present invention.

FIG. 8 is an explanatory diagram showing a schematic configuration of an ion trap mass spectrometer according to a seventh embodiment of the present invention.

FIG. 9 is an explanatory diagram showing a method of scanning a high frequency voltage and an auxiliary voltage in the mass spectrometer according to the eighth embodiment of the present invention.

FIG. 10 is a step explanatory view showing each electrode of the ion trap according to the conventional example.

FIG. 11 is a characteristic diagram showing a stable region and an unstable region in the range of a and q values for tracing a stable trajectory in the ion trap.

FIG. 12 is a diagram showing a numerical analysis result of the relationship between the amplitude ratio, the resolution, and the destabilization time between the auxiliary voltage and the high frequency voltage when q = 0.404.

FIG. 13 is an explanatory diagram showing a method of scanning a high frequency voltage and an auxiliary voltage of an ion trap mass spectrometer according to a conventional example.

[Explanation of symbols]

 1 sample source 2 sample introduction part 3 control part 4 main power supply for operation 5 electron gun for ion generation 6 ring electrode 7 upper end cap electrode 8 lower end cap electrode 9 detector 10 data processing part 11 auxiliary voltage power supply 12 end cap electrode Center port 13 End cap detection port 14 One-side emission auxiliary voltage power supply 15 Inter-electrode space

Claims (26)

[Claims] 1. An interelectrode space by applying at least a high frequency voltage of a DC voltage and a high frequency voltage from a main power supply between an annular ring electrode and two end cap electrodes arranged to face each other so as to sandwich the annular ring electrode. In a mass spectrometry method in which ions trapped in a quadrupole electric field generated in the electrode are emitted from the inter-electrode space to detect the mass of the ions, an auxiliary alternating current is applied to the end cap electrode to generate an auxiliary alternating electric field. A mass spectrometric method characterized in that an amplitude ratio between a voltage and the high frequency voltage is changed in accordance with a resolution required for mass spectrometric analysis of ions to be detected, and the ions are emitted. 2. An inter-electrode space is obtained by applying at least a high frequency voltage of a DC voltage and a high frequency voltage from a main power supply between an annular ring electrode and two end cap electrodes arranged to face each other so as to sandwich it. In a mass spectrometric method in which ions trapped in the quadrupole electric field generated in the system are emitted from the inter-electrode space to detect the mass of the ions, the mass of the ions within the range of the mass-to-charge ratio A mass spectrometric method characterized in that ions having different values of mass-to-charge ratio are sequentially detected by scanning the charge-to-charge ratio. 3. The mass spectrometric method according to claim 2, wherein the time allotted to the analysis of each ion is changed according to the mass-to-charge ratio of the ion to be detected. 4. A ring-shaped ring electrode and two end cap electrodes arranged to face each other so as to sandwich the ring-shaped ring electrode, and at least a high frequency voltage of a DC voltage and a high frequency voltage is provided between the ring electrode and the end cap electrode. Of the ions having a mass-to-charge ratio to be detected among the ions that are stably trapped in the quadrupole electric field created in the interelectrode space by applying In a mass spectrometer that destabilizes by generating a weak auxiliary AC electric field and emits the ion from the inter-electrode space to detect the mass of the ion, the auxiliary AC electric field is generated by applying the end cap electrode. Control means for changing the amplitude ratio between the auxiliary AC voltage and the high-frequency voltage according to the resolution required for the mass analysis of the ions to be detected. Mass spectrometer. 5. The mass spectrometer according to claim 4, wherein the control unit changes the amplitude ratio according to the value of the mass-to-charge ratio of each ion. 6. The mass spectrometer according to claim 4, wherein the control unit changes the amplitude ratio so that the half width of the mass spectrum of each ion becomes a target value. 7. The mass spectrometer according to claim 4, wherein the control means changes the amplitude ratio of the auxiliary AC voltage and the high frequency voltage to be smaller as the required resolution of the ions to be detected is higher. 8. The control means changes the amplitude ratio of the auxiliary AC voltage and the high frequency voltage to be smaller as the value of the mass-to-charge ratio of the ions to be detected is higher. Mass spectrometer. 9. The apparatus further comprises means for changing the amplitude of the auxiliary AC voltage so as to always satisfy the ratio of the auxiliary AC voltage and the high frequency voltage obtained from the resolution required for analysis of each ion. The mass spectrometer according to claim 4. 10. A means for scanning with scanning characteristics having different mass-to-charge ratios depending on which point of the characteristics that determine the stability of the trajectory of the ions oscillating in the space between the ion trap electrodes resonates. The mass spectrometer according to claim 4, further comprising: 11. A ring-shaped ring electrode and two end-cap electrodes arranged to face each other so as to sandwich the ring-shaped ring electrode, and at least a high-frequency voltage of a DC voltage and a high-frequency voltage is provided between the ring electrode and the end-cap electrode. Of the ions having a mass-to-charge ratio to be detected among the ions that are stably trapped in the quadrupole electric field created in the interelectrode space by applying Within a mass-to-charge ratio range of the ion to be detected in a mass spectrometer that destabilizes by generating a weak auxiliary AC electric field and emits the ion from the interelectrode space to detect the mass of the ion. And a means for scanning the mass-to-charge ratio, and scanning by the means to sequentially detect each ion having a different mass-to-charge ratio value with time. Analyzer. 12. The mass according to claim 11, further comprising means for changing a time allotted for analysis of each ion by the scanning means in accordance with a mass-to-charge ratio of ions to be detected. Analysis equipment. 13. The mass spectrometer according to claim 12, wherein the changing means allocates a sufficient time for the orbit of each ion to be destabilized and emitted as an analysis time of each ion. 14. The mass spectrometer according to claim 12, wherein the scanning means changes the scanning speed of the mass-to-charge ratio in accordance with the amplitude ratio of the auxiliary voltage and the high frequency voltage. 15. The mass according to claim 14, wherein the scanning means changes so that the scanning speed of the mass-to-charge ratio becomes slower as the amplitude ratio of the auxiliary voltage and the high frequency voltage becomes higher. Analysis equipment. 16. The mass spectrometer according to claim 12, wherein the scanning means changes the scanning speed of the mass-to-charge ratio according to the mass-to-charge ratio of the ions to be detected. 17. The scanning means changes the mass-to-charge ratio such that the scanning speed of the mass-to-charge ratio becomes slower as the value of the mass-to-charge ratio of the ions to be detected becomes higher. Mass spectrometer. 18. The mass spectrometer according to claim 11, wherein the scanning means scans the mass-to-charge ratio of the ions to be detected by scanning the amplitude of the high frequency voltage. 19. The mass of the object to be detected when the amplitude of the high-frequency voltage changes as represented by a + 1st-order function of the elapsed time of mass analysis of all ions in the range to be detected. 19. The mass spectrometer according to claim 18, wherein the range of the charge ratio is divided into at least two regions and scanning is performed so that the scanning speed of the high frequency voltage amplitude changes in each region. 20. The scanning means changes and scans the amplitude of the high-frequency voltage so as to be represented by a function of a positive order of at least +1 or less of the elapsed time of mass analysis of all ions in the detection target range. 19. The mass spectrometer according to claim 18, wherein: 21. The scanning means changes the amplitude of the high frequency voltage so that it is represented by a function of an order of +1/2 of the elapsed time of mass analysis of all ions in the detection target range, and scans. 19. The mass spectrometer according to claim 18, wherein: 22. The scanning means scans the mass-to-charge ratio of the ions to be detected by scanning the frequency of the high-frequency voltage.
The described mass spectrometer. 23. The mass spectrometer according to claim 11, wherein the scanning means scans the mass-to-charge ratio of the ions to be detected by scanning the magnitude of the DC voltage. 24. The mass spectrometer according to claim 11, wherein the scanning means scans the mass-to-charge ratio of the ions to be detected by scanning both the amplitude of the high frequency voltage and the DC voltage. apparatus. 25. The range of the mass-to-charge ratio of the ions to be detected is divided into two or more regions, and the mass-to-charge ratio of the ions to be detected and the amplitude ratio of the high frequency voltage and the auxiliary voltage are divided in each region. On the other hand, the mass spectrometer according to claim 11, further comprising means for scanning with different scanning characteristics. 26. The mass spectrometer according to claim 4, further comprising means for controlling a direction in which resonance ions are destabilized and emitted from the inter-electrode space.