阅读说明：本技术 离子迁移率分析装置 (Ion mobility analysis device ) 是由 有田义宣 于 2017-07-04 设计创作，主要内容包括：漂移电源部(12)的输出电压通过梯形电阻电路(10A)被适当地进行电阻分压,并被分别施加到形成离子输送区域(A)的多个环状电极(21)和形成漂移区域(B)的电阻管(4)。电压检测部(14)检测对电阻管(4)的高电位端部施加的电压,反馈控制部(15)控制漂移电源部(12)的输出电压以使检测电压为固定。在测定时,如果周围温度发生变化、或者装置被长时间连续地使用,则电阻管(4)的电阻值发生变化,但是通过反馈控制能够抑制伴随这样的变化而引起的中间电压(Vm)的变化,因此在电阻管(4)内形成的电场的强度和电位梯度稳定。由此,能够将测定的再现性和分辨率维持在较高的状态。(The output voltage of the drift power supply unit (12) is subjected to resistance voltage division appropriately by a ladder resistance circuit (10A), and is applied to a plurality of ring-shaped electrodes (21) forming an ion transport region (A) and a resistance tube (4) forming a drift region (B), respectively. A voltage detection unit (14) detects a voltage applied to a high potential end of the resistance tube (4), and a feedback control unit (15) controls the output voltage of the drift power supply unit (12) so that the detected voltage is constant. During measurement, if the ambient temperature changes or the device is used continuously for a long time, the resistance value of the resistance tube (4) changes, but the change of the intermediate voltage (Vm) caused by the change can be suppressed by feedback control, so that the intensity and the potential gradient of the electric field formed in the resistance tube (4) are stable. This can maintain the reproducibility and resolution of measurement in a high state.)

1. An ion mobility analysis device is characterized by comprising:

a) a drift electric field forming unit that forms an electric field corresponding to the applied voltage in a space for separating ions according to mobility;

b) an ion transport unit that forms an electric field for transporting ions originating from a sample component to the space, in accordance with an applied voltage;

c) a power supply unit that generates a predetermined direct-current voltage;

d) a voltage distribution unit that performs resistance voltage division on the output voltage generated by the power supply unit and applies the divided voltage to the ion transport unit and the drift electric field formation unit, respectively;

e) a voltage detection unit that detects a voltage applied to the drift electric field formation unit by the voltage distribution unit; and

f) and a control unit that controls the output voltage generated by the power supply unit so as to maintain the voltage detected by the voltage detection unit at a predetermined value.

2. An ion mobility analysis device is characterized by comprising:

a) a drift electric field forming unit that forms an electric field corresponding to the applied voltage in a space for separating ions according to mobility;

b) an ion transport unit that forms an electric field for transporting ions originating from a sample component to the space, in accordance with an applied voltage;

c) a power supply unit that generates a predetermined direct-current voltage;

d) a voltage divider that divides the output voltage generated by the power supply unit into resistors and distributes the divided voltages to the ion transport unit and the drift electric field forming unit, thereby adjusting the resistance value of a part of the resistors used for the division;

e) a voltage detection unit that detects a voltage applied to the drift electric field formation unit by the voltage distribution unit; and

f) and a control unit that adjusts a resistance value of the resistor that is adjustable by the voltage distribution unit so as to maintain the voltage detected by the voltage detection unit at a predetermined value.

3. The ion mobility analysis device according to claim 1,

at least one of the drift electric field forming part and the ion transport part is formed by arranging a plurality of annular electrodes at a predetermined interval in the axial direction thereof,

the voltage distribution unit applies different voltages to the plurality of ring-shaped electrodes.

4. The ion mobility analysis device according to claim 2,

at least one of the drift electric field forming part and the ion transport part is formed by arranging a plurality of annular electrodes at a predetermined interval in the axial direction thereof,

the voltage distribution unit applies different voltages to the plurality of ring-shaped electrodes.

5. The ion mobility analysis device according to claim 1,

at least one of the drift electric field forming section and the ion transport section is a tubular resistor having a space formed therein through which ions pass,

the voltage distribution unit applies a voltage to both ends of the tubular resistor.

6. The ion mobility analysis device according to claim 2,

at least one of the drift electric field forming section and the ion transport section is a tubular resistor having a space formed therein through which ions pass,

the voltage distribution unit applies a voltage to both ends of the tubular resistor.

7. The ion mobility analysis device according to claim 1,

the ion mobility analyzing apparatus further includes a detector that detects ions that have passed through a space in which an electric field is formed by the drift electric field forming unit.

8. The ion mobility analysis device according to claim 2,

the ion mobility analyzing apparatus further includes a detector that detects ions that have passed through a space in which an electric field is formed by the drift electric field forming unit.

9. The ion mobility analysis device according to claim 1,

the ion mobility analyzing apparatus further includes a mass spectrometer section that separates and detects ions that have passed through the space in which the electric field is formed by the drift electric field forming section, based on a mass-to-charge ratio.

10. The ion mobility analysis device according to claim 2,

the ion mobility analyzing apparatus further includes a mass spectrometer section that separates and detects ions that have passed through the space in which the electric field is formed by the drift electric field forming section, based on a mass-to-charge ratio.

Technical Field

The present invention relates to an ion mobility analyzer that separates and detects ions according to their mobility, or separates ions according to their mobility and then conveys them to an analysis unit such as a mass spectrometry unit at a subsequent stage.

Background

When ions derived from a compound in a sample are moved in a medium gas (or liquid) by the action of an electric field, the ions move at a speed proportional to mobility determined by the strength of the electric field, the size of the ions, and the like. Ion Mobility Spectrometry (IMS) is a measurement method for analyzing sample molecules by using the Mobility.

Fig. 4 is a schematic configuration diagram of a general ion mobility analyzer (see patent document 1 and the like).

The ion mobility analysis device includes: an ion source 1 using an electrospray ionization (ESI) method or the like, which ionizes component molecules in a liquid sample; a plurality of ring electrodes 21, the plurality of ring electrodes 21 forming an ion transport region a; a plurality of ring-shaped electrodes 41, the plurality of ring-shaped electrodes 41 forming a drift region B; a shutter (shutter gate)3 disposed between the ring electrode 21 of the last stage in the ion transport region a and the ring electrode 41 of the first stage in the drift region B; a detector 6 that detects ions; and an exit electrode 5 disposed between the ring-shaped electrode 41 of the last stage in the drift region B and the detector 6. Here, the ring- shaped electrodes 21 and 41 are represented by end faces obtained when the ring- shaped electrodes 21 and 41 are cut by a plane including the ion optical axis C as a central axis.

The annular electrodes 21 and 41 and the outlet electrode 5 are connected to a ladder resistance circuit 10B including a plurality of resistors, and a dc voltage generated by resistance-dividing a voltage V applied from a dc power supply, not shown, by the resistors of the ladder resistance circuit 10B is applied. As a result, a dc electric field indicating a falling potential gradient, that is, an acceleration of ions is formed in each of the ion transport region a and the drift region B in the ion moving direction (in the right direction in fig. 4). The potential gradient in the electric field formed in the ion transport region a and the potential gradient in the electric field formed in the drift region B can be appropriately adjusted by the value of the resistance constituting the ladder resistance circuit 10B. In the drift region B, a neutral diffusion gas flow is formed in a direction opposite to the acceleration direction accelerated by the electric field. Although not shown, a pulse-like voltage is applied to the gate 3 from a different power supply.

The ion mobility analyzer operates in the following manner.

In the ion source 1, various ions generated from a sample travel in the ion transport region a, and are temporarily blocked in front of the shutter 3 by a potential barrier formed at the shutter 3. Then, when the gate 3 is opened for a short time, ions are introduced into the drift region B in batches, that is, substantially simultaneously. The ions introduced into the drift region B travel by the action of the accelerating electric field while colliding with the opposing diffusion gas. In the middle of its travel, ions are spatially separated in the ion optical axis C direction according to ion mobility depending on the size, the steric structure, the valence, and the like of the ions, and the ions having different ion mobility pass through the exit electrode 5 with a time difference and reach the detector 6. When the electric field in the drift region B is a uniform electric field, the cross-sectional area of the collision between the ion and the diffusion gas can be estimated from the drift time required for the ion to pass through the drift region B.

Further, as described above, the ions are not directly detected after being separated according to the ion mobility, but the following structure may be adopted: these ions are introduced into a mass separator such as a quadrupole mass filter to further separate the ions according to the mass-to-charge ratio m/z, and then detected. Such an apparatus is known as an ion mobility-mass spectrometry apparatus (IMS-MS).

In the example shown in fig. 4, a structure in which a plurality of ring- shaped electrodes 21 and 41 are stacked (generally, a structure in which ring-shaped electrodes and ring-shaped insulating spacers are alternately stacked) is used to form electric fields for moving ions in the ion transport region a and the drift region B, respectively. In the present specification, a method of forming an electric field using such a structure is referred to as a "stack (stack) method".

On the other hand, patent document 2 and the like disclose an ion mobility analyzer including: instead of a plurality of ring-shaped electrodes, a resistance tube in which a resistance coating layer is formed on the inner circumferential surface of a cylindrical glass tube is used (see non-patent document 1 and the like). Fig. 5 is a schematic configuration diagram of such an ion mobility analyzer.

In this ion mobility analyzer, a predetermined direct current voltage is applied between both ends of the resistance tube 2 for the ion transport region a and the resistance tube 4 for the drift region B, whereby a uniform electric field for accelerating ions can be formed in the resistance tubes 2 and 4. In this case, since the resistance tubes 2 and 4 themselves are resistors, the ladder resistance circuit 10C can be configured to have a virtual resistance corresponding to each of the resistance tubes 2 and 4 as shown in fig. 5. In the present specification, a method of forming an electric field using such a structure is referred to as a "resistance tube method".

In the resistive tube type ion mobility analyzer as well, as in the stack type, the number of power sources to be used can be reduced by applying a voltage applied from the dc power source to the resistive tube 2 for the ion transport region a and the resistive tube 4 for the drift region B after performing resistance division by the ladder resistance circuit 10C.

However, both the stack system and the resistance tube system have the following problems.

The resistance value between both ends of a commercially available resistance tube changes relatively greatly depending on the temperature of the environment in which the resistance tube is used, the continuous use time, and the like. Fig. 6 is a graph showing the results of actually measuring the resistance value between both ends of a commercially available resistance tube. The temperature rise state at 150 ℃ is a state in which an actual usage state in the ion mobility analyzer is assumed, but the resistance value is reduced to around 1/2 in the initial state (room temperature). In addition, if continuously used for about 1000 hours, the resistance value increases to more than two times the resistance value from the initial time point of its temperature rise. The latter is presumed to be caused by adhesion of components in the atmosphere or the like to the resistance coating layer of the resistance tube.

In the ion mobility analyzer shown in fig. 5, when the resistance value of the resistance tube 4 changes due to temperature change or changes with time as described above, the voltage applied across the resistance tube 4 changes, and the electric field intensity in the drift region B changes. This causes a change in the velocity of ions passing through the drift region B, which leads to a decrease in device performance such as reproducibility and resolution of measurement.

On the other hand, in the stack-type ion mobility analyzer as shown in fig. 4, of the resistances included in the ladder resistance circuit 10B, the resistance for distributing a voltage to the plurality of ring electrodes 41 forming the drift region B is separated from the resistance for distributing a voltage to the plurality of ring electrodes 21 forming the ion transport region a, and the former is generally disposed at the nearest position to the drift region B. In the measurement, since the ring electrodes 41 forming the drift region B are maintained at a high temperature of about 150 to 200 ℃, the resistance for applying a voltage to these ring electrodes 41 is also at a considerably high temperature, but the ambient temperature of the resistance for applying a voltage to the ring electrodes 21 forming the ion transport region a is considerably lower than that. Therefore, the change in the resistance value due to temperature is different between the ion transport region a side and the drift region B side, thereby causing a change in the voltage applied between the first stage and the last stage in the ring-shaped electrode 41 forming the drift region B, resulting in a change in the electric field strength in the drift region B. As a result, similarly to the resistance tube method, there is a possibility that the device performance such as reproducibility and resolution of measurement may be degraded.

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made to solve the above problems, and an object of the present invention is to provide an ion mobility analyzer including: even when the ambient temperature changes or the device is used for a long time, the electric field strength in the drift region can be stably maintained, and high device performance can be maintained.

Means for solving the problems

An ion mobility analyzer according to a first aspect of the present invention, which has been made to solve the above problems, includes:

a) a drift electric field forming unit that forms an electric field corresponding to the applied voltage in a space for separating ions according to mobility;

b) an ion transport unit that forms an electric field for transporting ions originating from a sample component to the space, in accordance with an applied voltage;

c) a power supply unit that generates a predetermined direct-current voltage;

d) a voltage distribution unit that performs resistance voltage division on the output voltage generated by the power supply unit and applies the divided voltage to the ion transport unit and the drift electric field formation unit, respectively;

e) a voltage detection unit that detects a voltage applied to the drift electric field formation unit by the voltage distribution unit; and

f) and a control unit that controls the output voltage generated by the power supply unit so as to maintain the voltage detected by the voltage detection unit at a predetermined value.

In order to solve the above problem, an ion mobility analyzer according to a second aspect of the present invention includes:

a) a drift electric field forming unit that forms an electric field corresponding to the applied voltage in a space for separating ions according to mobility;

b) an ion transport unit that forms an electric field for transporting ions originating from a sample component to the space, in accordance with an applied voltage;

c) a power supply unit that generates a predetermined direct-current voltage;

d) a voltage divider that divides the output voltage generated by the power supply unit into resistors and distributes the divided voltages to the ion transport unit and the drift electric field forming unit, thereby adjusting the resistance value of a part of the resistors used for the division;

e) a voltage detection unit that detects a voltage applied to the drift electric field formation unit by the voltage distribution unit; and

f) and a control unit that adjusts a resistance value of the resistor that is adjustable by the voltage distribution unit so as to maintain the voltage detected by the voltage detection unit at a predetermined value.

In the ion mobility analyzing apparatus according to the first and second aspects of the present invention, the following configuration may be adopted:

at least one of the drift electric field forming part and the ion transport part is formed by arranging a plurality of annular electrodes at a predetermined interval in the axial direction thereof,

the voltage distribution unit applies different voltages to the plurality of ring-shaped electrodes.

In the ion mobility analyzing apparatus according to the first and second aspects of the present invention, the following configuration may be adopted:

at least one of the drift electric field forming section and the ion transport section is a tubular resistor having a space formed therein through which ions pass,

the voltage distribution unit applies a voltage to both ends of the tubular resistor.

That is, the drift electric field forming unit and the ion transport unit may be both of the stack type or the resistance tube type, or may be configured such that one of them is of the stack type and the other is of the resistance tube type.

For example, in the case where both the drift electric field forming section and the ion transport section are tubular resistors, that is, resistance tubes, the resistance value of the tubular resistor changes when the ambient temperature of the tubular resistor serving as the drift electric field forming section changes or changes with time due to long-term use. Although there is no problem if the resistance values of the tubular resistors of the ion transport unit also change at the same rate, the voltage applied to the tubular resistors serving as the drift electric field forming unit changes due to a change in the ratio of the resistance partial pressure in the voltage distribution unit, because the rate of change in the resistance values is not generally the same.

In the ion mobility analyzer according to the first aspect of the present invention, the voltage detector detects the voltage at predetermined time intervals, for example, and inputs the detected voltage to the controller. The control unit performs feedback control on the voltage value of the output voltage generated by the power supply unit to maintain the detected voltage at a predetermined value. That is, if the detected voltage changes in a high direction, control is performed to decrease the output voltage generated by the power supply unit in accordance with the rate of change thereof, and conversely, if the detected voltage changes in a low direction, control is performed to increase the output voltage generated by the power supply unit in accordance with the rate of change thereof. By such feedback control, the voltage applied to the tubular resistor body as the drift electric field forming portion is maintained substantially constant, and therefore the intensity and the potential gradient of the electric field formed by the drift electric field forming portion can be stably maintained without being affected by the ambient temperature and the change with time.

On the other hand, in the ion mobility analyzer according to the second aspect of the present invention, the resistance values of some of the resistors in the voltage distribution unit for performing voltage distribution by the resistor voltage division can be adjusted. The control unit adjusts the resistance value of the adjustable resistor so as to maintain the voltage detected by the voltage detection unit at a predetermined value without adjusting the power supply unit. As a result, as in the ion mobility analyzer of the first aspect, the intensity and potential gradient of the electric field formed by the drift electric field forming portion can be stably maintained without being affected by the ambient temperature and the change with time.

As a method of adjusting the resistance value, for example, a method of mechanically driving an operator (a lever or the like) for changing the resistance value of the analog variable resistor, a method of switching a plurality of resistors by a switch, or the like can be adopted as an appropriate method.

The ion mobility analyzer according to the present invention may be a device that directly detects ions separated according to the mobility, or a device that further separates and detects ions separated according to the mobility according to the mass-to-charge ratio in a mass spectrometer such as a quadrupole mass filter.

That is, as an embodiment of the ion mobility analyzer according to the present invention, the following configuration may be adopted: the ion mobility analyzing apparatus further includes a detector that detects ions that have passed through a space in which an electric field is formed by the drift electric field forming unit.

In another embodiment of the ion mobility analyzer according to the present invention, the ion mobility analyzer may be configured as follows: the ion mobility analyzing apparatus further includes a mass spectrometer section that separates and detects ions that have passed through the space in which the electric field is formed by the drift electric field forming section, based on a mass-to-charge ratio.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the ion mobility analyzer of the present invention, even when the ambient temperature changes or the device is used for a long time, the electric field strength and the electric potential gradient in the drift region that affect the movement speed of ions can be stably maintained. This can maintain the device performance such as reproducibility and resolution of measurement in a high state.

Drawings

Fig. 1 is a schematic configuration diagram of an ion mobility analyzer according to a first embodiment of the present invention.

Fig. 2 is a schematic configuration diagram of an ion mobility analyzer according to a second embodiment of the present invention.

Fig. 3 is a schematic configuration diagram of an ion mobility analyzer according to a third embodiment of the present invention.

Fig. 4 is a schematic configuration diagram of a general stack-type ion mobility analyzer.

Fig. 5 is a schematic configuration diagram of a general resistance tube type ion mobility analyzer.

Fig. 6 is a graph showing the results of actually measuring the resistance value between both ends of a commercially available resistance tube.

Detailed Description

[ first embodiment ]

An ion mobility analysis device according to a first embodiment of the present invention is described with reference to fig. 1.

Fig. 1 is a schematic configuration diagram of an ion mobility analyzer according to the present embodiment. In fig. 1, the same components as those of the devices shown in fig. 4 and 5 already described are denoted by the same reference numerals.

In the ion mobility analyzing apparatus according to the first embodiment, the ion transport region a is formed by the plurality of ring-shaped electrodes 21, while the drift region B is formed by the resistance tube 4. That is, the ion transport region a has a stack structure, and the drift region B has a resistance tube structure. As described above, since the resistance tube 4 itself is a resistor, it can be considered that a virtual resistance (a resistance indicated by a broken line in fig. 1) formed by the resistance tube 4 exists in the ladder resistance circuit 10A for applying a voltage to the resistance tube 4 and each of the ring-shaped electrodes 21. Further, this is also the same in the second embodiment below.

One end of the ladder resistance circuit 10A is grounded, and the other end is applied with a dc voltage having a voltage value V by the drift power supply unit 12. That is, the output voltage of the drift power supply unit 12 is subjected to resistance voltage division by the ladder resistance circuit 10A and then applied to the resistance tube 4 and the plurality of ring electrodes 21. On the other hand, the gate 3 is applied with a pulse-like voltage by the gate power supply unit 13. Further, a voltage obtained by adding the output voltage V of the drift power supply unit 12 and the output voltage Vi of the ion source power supply unit 17 by the adding unit 18 is applied to the ion source 1. The drift power supply unit 12 and the gate power supply unit 13 are controlled by a control unit 16. The ion source power supply unit 17 is a floating power supply. The voltage detector 14 detects a voltage applied to the high-potential-side end of the resistance tube 4 (hereinafter referred to as an "intermediate voltage"), and inputs the detection result to the Feedback (FB) controller 15. The feedback control unit 15 performs an operation corresponding to the input voltage detection result, and controls so as to adjust the output voltage generated by the drift power supply unit 12.

In general, the output voltage V of the drift power supply unit 12 is a high voltage of several kilovolts (kV) to several tens of kilovolts (kV), and a voltage higher than the output voltage V (about 4kV to 5kV in the case of an ion source using the ESI method) needs to be applied to the ion source 1. If such a high voltage is generated by the ion source power supply unit alone, the size of the power supply becomes considerably large and heavy, and the cost also increases. In contrast, in this ion mobility analyzing apparatus, since the output voltage of the drift power supply unit 12 and the output voltage of the ion source power supply unit 17 are added and applied to the ion source 1 as described above, the ion source power supply unit 17 only needs to output the voltage required for ionization in the ion source 1, and thus cost reduction and size and weight reduction of the power supply can be achieved.

In the ion mobility analyzer of the present embodiment, the measurement operation itself for separating and detecting ions derived from a sample component according to mobility is the same as that of the conventional apparatus already described, and therefore, the description thereof is omitted.

Next, feedback control of a characteristic drift voltage in the ion mobility analyzer of the present embodiment will be described.

When the measurement is performed, the voltage detection unit 14 repeatedly detects the voltage at predetermined time intervals, for example.

At this time, the voltage value of the intermediate voltage detected at the measurement start time point is defined as Vm. In addition, in the ladder resistance circuit 10A, it is assumed that: the resistance values of the resistor provided between the resistance tube 4 and the outlet electrode 5 and the resistor provided between the outlet electrode 5 and the ground are sufficiently small compared to the resistance value R of the resistance tube 4, and therefore can be ignored (that is, can be regarded as 0), and the series resistance value of the plurality of resistors provided between the first stage ring electrode 21 and the resistance tube 4 is R. Then, the voltage value Vm of the intermediate voltage is expressed by the following expression (1).

Vm＝V·{R/(r+R)}…(1)

When the resistance value R of the resistance tube 4 becomes R 'due to a change in the ambient temperature or the like, the voltage value Vm of the intermediate voltage accordingly becomes Vm'. The feedback control section 15 recognizes the voltage change based on the detection voltage result obtained by the voltage detection section 14. Then, the drift power supply section 12 is controlled to change the output voltage in accordance with the voltage change amount. Specifically, the drift power supply unit 12 is controlled so that the voltage value V of the output voltage becomes a voltage value V' obtained by the following equation (2).

V’＝V·(Vm/Vm’)…(2)

The drift power supply unit 12 changes its output voltage in accordance with the feedback control. Thereby, the intermediate voltage is restored from Vm' to Vm, and the voltage between both ends of the resistance tube 4 is maintained constant. As a result, the strength and potential gradient of the electric field formed in the resistance tube 4 are kept constant without being affected by temperature change and change with time.

[ second embodiment ]

Fig. 2 is a schematic configuration diagram of an ion mobility analyzing apparatus according to a second embodiment. In fig. 1, the same components as those of the devices shown in fig. 1, 4, and 5 already described are denoted by the same reference numerals.

Points different from the ion mobility analysis device of the first embodiment will be described. In the ion mobility analyzer according to the second embodiment, the variable resistor 11 capable of adjusting the resistance value is electrically connected between both ends of a series circuit (that is, a resistor having the series resistance value r) of a plurality of resistors provided between the first stage ring electrode 21 and the resistance tube 4 in the ladder resistance circuit 10A. The feedback control unit 15 is configured to control the resistance value of the variable resistor 11, not the drift power supply unit 12.

When the resistance value R of the resistance tube 4 becomes R 'due to a change in the ambient temperature or the like, the voltage value Vm of the intermediate voltage becomes Vm'. This voltage value Vm' can be represented by the following formula (3).

Vm’＝V·R’/(r+R’)…(3)

The formula (3) is the following formula (4).

R’＝r/{(V/Vm’)-1}…(4)

Here, in order to obtain the original voltage value Vm by changing the resistance value r to r', the ratio of the resistance voltage division needs to satisfy the following expression (5).

R/(r+R)＝R’/(r+R’)…(5)

The formula (5) is arranged to be formula (6),

r’＝r×(R’/R)…(6)

therefore, the resistance value r' may be as follows.

r’＝r²/[R·{(V/Vm)-1}]…(7)

The feedback control unit 15 adjusts the resistance value of the variable resistor 11 based on the resistance value obtained by the calculation. As a result, the voltage value of the intermediate voltage can be maintained substantially constant, and the intensity and potential gradient of the electric field formed in the resistance tube 4 can be stably maintained, as in the first embodiment.

Here, although the variable resistor 11 is connected between both ends of the series circuit of the plurality of resistors provided between the first stage ring electrode 21 and the resistance tube 4 in the ladder resistance circuit 10A, it is obvious that the voltage value of the intermediate voltage can be maintained constant by connecting the variable resistor in parallel with the resistance tube 4 and adjusting the resistance value of the variable resistor.

[ third embodiment ]

Fig. 3 is a schematic configuration diagram of an ion mobility analyzing apparatus according to a third embodiment. In this ion mobility analyzer, drift region B is formed by a plurality of ring-shaped electrodes 41 arranged inside insulating tube 40. That is, the drift region B has a stack structure. In this configuration, the voltage applied to the first-stage ring electrode 41, that is, the voltage value of the intermediate voltage can be maintained constant by the operation exactly the same as that of the first embodiment.

It is obvious that the drift region B may be configured in a stack manner as in the third embodiment, and the resistance value of the variable resistor 11 may be adjusted instead of the output voltage of the drift power supply unit 12 as in the second embodiment.

In addition, in the ion mobility analyzing apparatuses according to the first to third embodiments, it is also possible to form the ion transporting region a by a resistance tube, as is apparent.

In the ion mobility analyzing apparatus according to each of the above embodiments, the ions separated by the ion mobility in the drift region B are detected by the detector 6, but the ions separated by the ion mobility may be introduced into a mass separator such as a quadrupole mass filter, further separated by a mass-to-charge ratio, and then detected.

The above-described embodiments are merely examples of the present invention, and it is needless to say that the present invention is not limited to the above-described embodiments and the various modifications, and it is to be understood that the present invention is intended to cover modifications, corrections, and additions within the scope of the present invention.

Description of the reference numerals

1: an ion source; 2: a resistance tube; 21: a ring-shaped electrode; 3: a gate; 4: a resistance tube; 40: an insulating tube; 41: a ring-shaped electrode; 5: an exit electrode; 6: a detector; 10A, 10B, 10C: a ladder resistance circuit; 11: a variable resistor; 12: a drift power supply unit; 13: a gate power supply unit; 14: a voltage detection unit; 15: a Feedback (FB) control unit; 16: a control unit; 17: an ion source power supply unit; 18: an addition unit; a: an ion transport region; b: a drift region; c: ion optic axis.