CN112331550A - Ion gate for ion mobility spectrometer and control method thereof - Google Patents
Ion gate for ion mobility spectrometer and control method thereof Download PDFInfo
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- 238000000034 method Methods 0.000 title claims abstract description 18
- 150000002500 ions Chemical class 0.000 claims abstract description 328
- 230000005012 migration Effects 0.000 claims abstract description 41
- 238000013508 migration Methods 0.000 claims abstract description 41
- 230000005684 electric field Effects 0.000 claims abstract description 38
- 239000002184 metal Substances 0.000 claims description 8
- 230000009471 action Effects 0.000 claims description 3
- 238000001514 detection method Methods 0.000 abstract description 12
- 230000035945 sensitivity Effects 0.000 abstract description 8
- 230000006835 compression Effects 0.000 abstract description 7
- 238000007906 compression Methods 0.000 abstract description 7
- 230000008569 process Effects 0.000 abstract description 6
- 238000002347 injection Methods 0.000 abstract description 5
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- 230000008859 change Effects 0.000 abstract description 4
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- 230000000737 periodic effect Effects 0.000 abstract description 2
- 230000001105 regulatory effect Effects 0.000 abstract description 2
- DQWPFSLDHJDLRL-UHFFFAOYSA-N triethyl phosphate Chemical compound CCOP(=O)(OCC)OCC DQWPFSLDHJDLRL-UHFFFAOYSA-N 0.000 description 20
- 238000001871 ion mobility spectroscopy Methods 0.000 description 13
- 238000001228 spectrum Methods 0.000 description 8
- -1 acetone dimer ion Chemical class 0.000 description 7
- 230000008901 benefit Effects 0.000 description 5
- 239000000178 monomer Substances 0.000 description 5
- 238000000926 separation method Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 229940090044 injection Drugs 0.000 description 4
- 238000005468 ion implantation Methods 0.000 description 4
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 3
- 230000007704 transition Effects 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 230000035515 penetration Effects 0.000 description 2
- 230000004304 visual acuity Effects 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 1
- 239000002019 doping agent Substances 0.000 description 1
- 238000002513 implantation Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000002000 scavenging effect Effects 0.000 description 1
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Abstract
The invention discloses an ion gate for an ion mobility spectrometer and a control method thereof. The ion gate is composed of two Bradbury-Nielsen type ion gates arranged in parallel; by regulating and controlling the periodic change of the two Bradbury-Nielsen type ion gates among the states of opening the door, compressing the field and closing the door respectively, ions existing between the two Bradbury-Nielsen type ion gates can be injected into an ion migration area without discrimination, and two-stage electric field compression is carried out on the injected ion clusters in the process, so that the resolution capability and the detection sensitivity of the ion mobility spectrometer on the ions in the full mobility K range are improved at the same time. Compared with a tri-state ion gate which realizes ion non-discrimination injection by utilizing three parallel grid mesh electrodes, the ion gate is only provided with the ion gate electrodes in two planes, and the loss caused by collision of ions with the electrodes when passing through the plane of the ion gate electrodes can be effectively reduced.
Description
Technical Field
The invention relates to an ion gate of an important component of an ion mobility tube in an ion mobility spectrometer and a control method thereof, in particular to an ion gate formed by two Bradbury-Nielsen type ion gates which are arranged in parallel.
Background
Ion Mobility Spectrometry (IMS) requires an Ion gate which is periodically opened to inject Ion packets into an Ion Mobility region to realize separation and detection of target ions. The time width of ion packets and the total amount of ions injected into the ion gate in the mobility region determine the Resolving Power (R) and the detection sensitivity of the ion mobility spectrometry.
For IMS with fixed migration zone length L, R is the time w for opening the door by the ion gateinjAnd peak broadening due to cluster migration (16 k)BTln2/eUd)1/2(L2/KUd) The decision is as shown in equation 1. When the instrument parameters are fixed, the peak broadening caused by ion cluster migration is fixed, and the opening time w of the ion gate is fixedinjBecomes the only determinant of R: w is ainjThe smaller the R, the higher the R.
Wherein L is an ion mobility region length, and K is an ion mobility (K ═ K)0(T/273.5) (760/P), T is temperature and P is pressure), UdIs the total voltage of the transition region, tdIs the ion peak migration time, w0.5Is the half-peak width of the ion peak, winj16k for ion door opening timeBTln2/eUdResulting in a peak broadening coefficient for ion diffusion.
The Bradbury-Nielsen type ion gate (BNG) is the ion gate configuration commonly employed in current commercial IMS instruments. In 2012, professor in the oceans in the university of jungle article discovered, when studying the effect of BNG closing voltage on IMS resolution: when the BNG is closed, the electric field for closing the door permeates toward the ion migration region and the ion reaction region which are adjacent to the BNG. Penetration of the gate-closing electric field into the transition region, causing a transient enhancement of the electric field in the transition region in the immediate vicinity of the ion gate region, in time domain w, to ion packets passing through the BNGinjThe compression is carried out, so that the half-peak width of the ion peak actually detected by the IMS is narrowed, and the resolution capability of the IMS is improved[11](ii) a However, the penetration of the electric field for closing the door simultaneously causes ion scavenging zones to be generated on both sides of the plane of the BNG electrode, whose axial width is comparable to the BNG filament spacing (typically, the filament spacing is such thatAt 1mm, the average width of the ion depletion region is about 1 mm). On the one hand, the time w for opening the door at BNGinjOnly ions passing through the ion clearance area can enter the ion migration area to be separated and detected, so that the actual time width of ion clusters injected into the IMS migration area by BNG is far shorter than the door opening time of BNG, and the IMS detection sensitivity is reduced; on the other hand, after the BNG door opening time is over, the BNG door closing electric field will pull back a part of the ions that have entered the IMS mobility region to the BNG electrode for consumption at the ion clearance region formed at the side of the BNG adjacent to the IMS mobility region, further reducing the IMS detection sensitivity.
In order to eliminate the ion mobility K discrimination effect of the ion gate in the ion implantation process, Ansgar Kirk et al (anal. chem.,2018,90,5603) designs a tri-state ion gate by using three parallel grid mesh electrodes, the gate opening time of the ion gate can be reduced to 1 μ s, and the ion mobility K discrimination phenomenon in the ion implantation process is basically eliminated. Chen hong et al (anal. chem.,2019,91, 9138; CN 201811381284.8; CN201811381337.6) further improve the control mode of the ion gate closing voltage in the tri-state ion gate, develop a tri-state ion gate with two-stage electric field compression effect, and realize the synchronous improvement of the resolution capability and the sensitivity of the ion mobility spectrum. Similar work also includes low ion mobility K discriminating ion gates based on three parallel grid electrode designs by cheng et al (CN 109659219B). Three parallel grid mesh electrodes are used in the work, ions need to pass through the planes of the multiple layers of ion gate electrodes in the ion implantation process, the loss caused by the collision of the ions with the ion gate electrodes is serious, and the opening time w of the ion gate is causedinjLess reduction in sensitivity.
For this reason, old et al (CN110491765B) developed a new BNG gate voltage control method, which reduces the ion mobility discrimination effect of BNG during ion implantation to some extent. However, it is still impossible to achieve a discriminationless implantation of ions in the full mobility K range like a tri-state ion gate. The advantage of high ion transmission efficiency brought by the BNG single electrode plane cannot be fully utilized.
Disclosure of Invention
The invention aims to provide an ion gate and a control method for ion mobility spectrometer, which can perform two-stage electric field compression on injected ion clusters in the ion injection process, thereby realizing high-resolution identification and high-sensitivity detection of ions in the full mobility K range by the ion mobility spectrometer.
In order to achieve the purpose, the invention adopts the technical scheme that:
an ion gate for an ion mobility spectrometer comprises an ion mobility tube, wherein the ion mobility tube is composed of an ion source, an ionization region, the ion gate, a migration region and an ion receiving electrode which are sequentially arranged along an ion migration direction;
the ion gate is positioned between the ionization region and the migration region;
the ion gate is composed of electrodes arranged in two planes which are parallel to each other and are spaced by 1-5 mm, the plane close to the ionization region is a first ion gate plane, the plane close to the migration region is a second ion gate plane, the first ion gate plane and the second ion gate plane are both vertical to the ion migration direction, and the electrode of the first ion gate plane and the electrode of the second ion gate plane are oppositely arranged;
the electrode in the first ion gate plane is a strip electrode or an annular electrode; when the electrodes are strip-shaped electrodes, more than 4 strip-shaped electrodes with even numbers are arranged in parallel from top to bottom at intervals, from top to bottom, the strip-shaped electrodes with odd numbers are used as first gate electrodes, and the strip-shaped electrodes with even numbers are used as second gate electrodes; or, when the electrode is a ring electrode, more than 4 ring electrodes which are even number and are concentric with the geometric center are arranged at intervals from inside to outside, and from inside to outside, the ring electrodes with odd number are used as first gate electrodes, and the ring electrodes with even number are used as second gate electrodes;
the electrode in the second ion gate plane is a strip electrode or an annular electrode; more than 4 even number of strip-shaped electrodes are arranged in parallel from top to bottom at intervals, from top to bottom, the odd number of strip-shaped electrodes are used as third gate electrodes, and the even number of strip-shaped electrodes are used as fourth gate electrodes; or, when the electrode is a ring electrode, more than 4 ring electrodes with the same geometric center are arranged at intervals from inside to outside, the odd ring electrodes are used as third gate electrodes, and the even ring electrodes are used as fourth gate electrodes;
the first gate electrode 3-1, the second gate electrode 3-2, the third gate electrode 3-3 and the fourth gate electrode 3-4 are insulated from each other.
Further, the first gate electrode, the second gate electrode, the third gate electrode and the fourth gate electrode are respectively connected with four direct current power supplies; preferably, the direct current power supply is a pulse direct current high voltage power supply.
Further, the strip-shaped electrode is a metal wire or a spiral linear electrode wound on a cylinder or a metal sheet or a metal mesh sheet;
the annular electrode is a circular ring electrode or a square ring electrode.
Further, the number of the first gate electrode, the second gate electrode, the third gate electrode and the fourth gate electrode is equal.
The invention also provides an ion transfer tube comprising the ion gate.
The invention also provides an ion mobility spectrometer comprising the ion mobility tube.
The invention also provides a control method of the ion gate, which is carried out according to a first preset time interval t1A second predetermined time interval t2A third predetermined time interval t3Sequentially applying electric potentials to the first gate electrode, the second gate electrode, the third gate electrode and the fourth gate electrode;
at a first predetermined time interval t1In the first gate electrode and the second gate electrode, a voltage V is applied simultaneously2Third gate electrode applying potential V1Fourth gate electrode applying potential V3The ion gate is opened at the first ion gate plane and closed at the second ion gate plane, a uniform direct current electric field pointing to the ion gate direction along the ion source is formed in the ionization region, a direct current electric field pointing to the second ion gate plane direction along the first ion gate plane is formed in the ion gate, and ions in the ionization region enter the ion gate through the first ion gate plane and are stopped at the second ion gate plane;
at a second predetermined time interval t2In which a first gate electrode and a second gate electrode are simultaneously applied with a potential V6The third gate electrode and the fourth gate electrode simultaneously apply a potential V1A direct current electric field pointing to the direction of an ion source along an ion gate is formed in the ionization region, ions in the ionization region move towards the direction of the ion source, a uniform direct current electric field with unchanged direction and enhanced intensity is formed in the ion gate, a uniform direct current electric field pointing to the direction of an ion receiving electrode along the ion gate is formed in the migration region, the electric field intensity in the ion gate is far higher than that in the migration region, and ions existing between the plane of the first ion gate and the plane of the second ion gate are compressed through the plane of the second ion gate and are all injected into the migration region;
at a third predetermined time interval t3In the first gate electrode, a potential V is applied2Second gate electrode applying potential V4The third gate electrode and the fourth gate electrode simultaneously apply a potential V5The ion gate is turned off at the first ion gate plane, a direct current electric field pointing to the ion gate direction along the ion source 1 is formed in the ionization region, ions in the ionization region are cut off at the first ion gate plane, a direct current electric field gradually weakened in the direction pointing to the ion receiving electrode along the ion gate is formed in the migration region, and the ions in the migration region sequentially reach the ion receiving electrode under the action of the direct current electric field to be detected;
potential V1Potential V2Potential V3Potential V4Potential V5And potential V6Are the same and the absolute value of the potential increases in sequence.
Further, a first predetermined time interval t10.05-1 ms, a second preset time interval t20.005-0.2 ms, a third preset time interval t31-10 ms;
further, at a first preset time interval t1A second predetermined time interval t2And a third predetermined time interval t3The summation of (a) constitutes one complete time period for the ion gate to operate;
when the ion migration tube works, the potentials applied to the first gate electrode, the second gate electrode, the third gate electrode and the fourth gate electrode of the ion gate 3 are periodically and circularly adjusted according to the time period.
The ion gate is composed of two Bradbury-Nielsen type ion gates arranged in parallel, the planes of electrodes of the two Bradbury-Nielsen type ion gates are perpendicular to the ion migration direction, and the distance between the two planes is kept to be 1-5 mm; by regulating and controlling the periodic change of the two Bradbury-Nielsen type ion gates among the states of opening the door, compressing the field and closing the door respectively, ions existing between the two Bradbury-Nielsen type ion gates can be injected into an ion migration area without discrimination, and two-stage electric field compression is carried out on the injected ion clusters in the process, so that the resolution capability and the detection sensitivity of the ion mobility spectrometer on the ions in the full mobility K range are improved at the same time. Compared with a tri-state ion gate which realizes ion non-discrimination injection by utilizing three parallel grid mesh electrodes, the ion gate is only provided with the ion gate electrodes in two planes, and the loss caused by collision of ions with the electrodes when passing through the plane of the ion gate electrodes can be effectively reduced.
The invention has the advantages that:
the invention only adds a layer of BNG electrode plane on the basis of the original BNG electrode plane in the ion migration tube, thereby retaining the advantage of high ion transmission efficiency of BNG to a certain extent; meanwhile, through controlling the voltage of each gate electrode, the ion non-discrimination injection in the full mobility K range can be realized, and the injected ion cluster is subjected to two-stage electric field compression, so that the resolution capability and the detection sensitivity of the ion mobility spectrometer on the ions in the full mobility K range are improved at the same time.
Drawings
Fig. 1 is a schematic cross-sectional view of an ion mobility tube using the disclosed ion gate. Wherein: 1. an ion source; 2. an ionization region; 3. an ion gate; 3-1, a first gate electrode; 3-2, a second gate electrode; 3-3, a third gate electrode; 3-4, a fourth gate electrode; 4. a migration zone; 5. an ion receiving electrode; 6. a float gas inlet; 7. a sample gas inlet; 8. and an air outlet.
Fig. 2 is a diagram of the disclosed gate electrode potential waveform for the ion gate of fig. 1. Wherein the potential of the first gate electrode 3-1 is at V2And V6Is changed between, the second gate electrode 3-2At a potential of V2、V4And V6Is changed, the potential of the third gate electrode 3-3 is at V1And V5Is changed, the potential of the fourth gate electrode 3-4 is at V1、V3And V5Change in between; t is t1＝1ms，t2＝0.05ms，t3＝10ms，t1Represents the time taken for the ions to fill the gap between the two gate electrode planes of the ion gate, t2Indicating the opening time, t, of the ion door3Indicating the time of separation and detection of implanted ion clusters within the mobility region; v1＝5910V，V2＝6090V，V3＝6110V，V4＝ 6290V，V5＝6410V，V6＝6590V。
Fig. 3 is a waveform diagram of a gate electrode potential used when the ion gate disclosed in fig. 1 adopts a Bradbury-Nielsen type ion gate control method disclosed in patent CN 110491765B. Wherein the potential of the first gate electrode 3-1 is at V2And V6Is changed, the potential of the second gate electrode 3-2 is at V2、V4And V6The potential of the third gate electrode 3-3 and the fourth gate electrode 3-4 is constant at V1；t1＝0.05ms，t2＝ 1ms，t3＝10ms，t1Indicating the opening time, t, of the ion door2Denotes the time of application of the compression electric field, t3Indicating the time of separation and detection of implanted ion clusters within the mobility region; v1＝5910V，V2＝6090V，V4＝6290 V，V6＝6590V。
Fig. 4 is a waveform diagram of a gate electrode potential used when the ion gate disclosed in fig. 1 adopts a conventional control manner of a Bradbury-Nielsen type ion gate. Wherein the voltage of the first gate electrode 3-1 is constant at V2The potential of the second gate electrode 3-2 is at V2And V4The potential of the third gate electrode 3-3 and the fourth gate electrode 3-4 is constant at V1；t1＝0.05ms，t2＝1ms，t3＝10ms，t1Indicating the opening time, t, of the ion door2And t3Both represent the separation and detection time of the implanted ion packets within the migration zone; v1＝5910V，V2＝6090V， V4＝6290V。
Fig. 5 is a comparison of ion mobility spectra of 20ppbv triethyl phosphate (TEP) obtained by the ion gate disclosed in fig. 1 using three different ion gate electrode potential control methods, with the ion gate open time being 0.05ms each. Wherein (a) is a TEP spectrum under the gate electrode potential waveform shown in fig. 2, (b) is a TEP spectrum under the gate electrode potential waveform shown in fig. 3, and (c) is a TEP spectrum under the gate electrode potential waveform shown in fig. 4.
Fig. 6 is a block diagram of the structural area of an ion gate within an ion mobility tube according to the present disclosure.
Detailed Description
The following non-limiting examples will allow one of ordinary skill in the art to more fully understand the present invention, but are not intended to limit the invention in any way. The present invention will be described in further detail with reference to the accompanying drawings.
In the description of the present invention, it is to be understood that the orientation or positional relationship indicated by the directional terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc., are generally based on the orientation or positional relationship shown in the drawings, and are used for convenience of description and simplicity of description only, and in the absence of any contrary indication, these directional terms are not intended to indicate and imply that the device or element so referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore should not be considered as limiting the scope of the present invention: the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.
Example 1
An ion mobility tube using the disclosed ion gate is shown in fig. 1 and 6. The ion mobility spectrometer comprises an ion mobility tube, wherein the ion mobility tube consists of an ion source 1, an ionization region 2, an ion gate 3, a mobility region 4 and an ion receiving electrode 5 which are sequentially arranged from left to right; the ion gate 3 is located between the ionization region 2 on the left side and the mobility region 4 on the right side; the ion source 1 of the ion transfer tube is63Ni, the length of the ionization region 2 is 30mm, the inner diameter is 20mm, and the length of the migration region 4 is 96mm, and the inner diameter is 20 mm; the ion gate 3 is composed of a first gate electrode 3-1, a second gate electrode 3-2,The third gate electrode 3-3 and the fourth gate electrode 3-4 are formed by 20 metal wires with the wire diameter of 0.05mm in parallel and at equal intervals of 1mm, wherein the first gate electrode 3-1, the second gate electrode 3-2, the third gate electrode 3-3 and the fourth gate electrode 3-4 are formed by a plurality of metal wires with the wire diameter of 0.05mm in parallel and at equal intervals of 1 mm; the first gate electrode 3-1 and the second gate electrode 3-2 are arranged in an interdigital and equal-silk-spacing manner in a first ion gate plane adjacent to the ionization region 2 to form a first Bradbury-Nielsen type ion gate, the third gate electrode 3-3 and the fourth gate electrode 3-4 are arranged in an interdigital and equal-silk-spacing manner in a second ion gate plane adjacent to the migration region 4 to form a second Bradbury-Nielsen type ion gate, and the two ion gate planes are both vertical to the axial direction of the ion migration tube and are spaced by 3 mm. The total potential 7890V is applied to the ion mobility tube, and potentials 6090V, 5910V and 150V are formed at the positions of the first ion gate plane, the second ion gate plane and the shielding grid in front of the ion receiver 5, respectively, by a resistor chain connected to the ion mobility tube. The ion transfer tube was operated at 100 deg.C, the drift gas flow rate was 50mL/min, the sample gas was 20ppbv of triethyl phosphate (TEP), the flow rate was 10mL/min, and 20ppmv of acetone as a dopant was introduced with the sample gas, the flow rate was 10 mL/min.
The first gate electrode 3-1, the second gate electrode 3-2, the third gate electrode 3-3 and the fourth gate electrode 3-4 are respectively connected with four pulse direct-current high-voltage power supplies;
at a first predetermined time interval t11ms, a second predetermined time interval t20.05ms, third predetermined time interval t3Applying the potentials shown in fig. 2 to the first gate electrode 3-1, the second gate electrode 3-2, the third gate electrode 3-3, and the fourth gate electrode 3-4 in sequence for 10 ms;
at a first predetermined time interval t1The first gate electrode 3-1 and the second gate electrode 3-2 apply the voltage V simultaneously for 1ms26090V, the third gate electrode applies a potential V15910V, the fourth gate electrode applies a potential V36110V, the ion gate 3 is opened at the first ion gate plane and closed at the second ion gate plane, a direct current uniform electric field pointing to the ion gate 3 direction along the ion source 1 is formed in the ionization region 2, a direct current electric field pointing to the second ion gate plane direction along the first ion gate plane is formed in the ion gate 3, and ions in the ionization region 2Entering the ion gate through the first ion gate plane and being cut off at the second ion gate plane;
at a second predetermined time interval t2The first gate electrode 3-1 and the second gate electrode 3-2 apply the potential V simultaneously within 0.05ms66590V, the third gate electrode 3-3 and the fourth gate electrode 3-4 apply a potential V simultaneously15910V, forming a direct current electric field in the ionization region 2 along the direction of the ion gate 3 pointing to the ion source 1, enabling ions in the ionization region 2 to move towards the ion source 1, forming a uniform direct current electric field with unchanged direction and enhanced strength in the ion gate 3, forming a direct current uniform electric field in the migration region 4 along the direction of the ion gate 3 pointing to the ion receiving electrode 5, wherein the electric field strength in the ion gate 3 is far higher than that in the migration region 4, and ions existing between the first ion gate plane and the second ion gate plane are compressed through the second ion gate plane and are all injected into the migration region 4;
at a third predetermined time interval t3The first gate electrode 3-1 applies a potential V for 10ms26090V, the second gate electrode 3-2 applies a potential V46290V, the third gate electrode 3-3 and the fourth gate electrode 3-4 simultaneously apply a potential V56410V, the ion gate 3 is turned off at the first ion gate plane, a direct current electric field pointing to the ion gate 3 along the ion source 1 is formed in the ionization region 2, ions in the ionization region 2 are cut off at the first ion gate plane, a direct current electric field gradually weakened in the direction pointing to the ion receiving electrode 5 along the ion gate 3 is formed in the migration region 4, and ions in the migration region 4 reach the ion receiving electrode successively under the action of the direct current electric field to be detected;
potential V1Potential V2Potential V3Potential V4Potential V5And potential V6The values of (A) are 5910V, 6090V, 6110V, 6290V, 6410V and 6590V in this order.
At a first predetermined time interval t11ms, a second predetermined time interval t20.05ms and a third predetermined time interval t3The sum of 10ms and t of 11.05ms constitutes a complete time period for the operation of the ion gate 3; t is t1Represents the time taken for the ions to fill the gap between the two gate electrode planes of the ion gate 3, t2Indicates to leaveOpening time of the sub-door 3, t3Indicating the time of separation and detection of the implanted ion clusters in the migration zone 4;
when the ion mobility tube is in operation, the potentials applied to the first gate electrode 3-1, the second gate electrode 3-2, the third gate electrode 3-3, and the fourth gate electrode 3-4 of the ion gate 3 periodically change with a period of 11.05ms according to the potential change timing shown in fig. 2.
Figure 5a shows an ion mobility spectrum of 20ppbv triethyl phosphate (TEP) obtained with the ion gate disclosed in figure 1 operating at the gate electrode potential waveform shown in figure 2. Wherein, the signal intensity of the acetone dimer ion peak, the TEP monomer ion peak and the TEP dimer ion peak is 555pA, 147pA and 77.5pA respectively, and the resolution capability is 108, 84 and 65 respectively.
Comparative example 1
In order to compare the advantages of the ion gate disclosed in fig. 1 and its control scheme (shown in fig. 2), an ion mobility spectrum of 20ppbv triethyl phosphate (TEP) was obtained at the same time as the ion gate disclosed in fig. 1 operated with the Bradbury-Nielsen type ion gate potential waveform disclosed in patent CN110491765B, as shown in fig. 5 b. Wherein, the signal intensity of the acetone dimer ion peak, the TEP monomer ion peak and the TEP dimer ion peak is 234pA, 26pA and 0pA respectively, and the resolution capability is 80, 62 and 0 respectively. The ionic TEP dimer with the smaller mobility K cannot be detected, and in addition, the signal intensity of the acetone dimer ionic peak and the TEP monomer ionic peak is reduced, and the resolving power is also reduced.
Comparative example 2
In order to compare the advantages of the ion gate disclosed in fig. 1 and its control scheme (shown in fig. 2), an ion mobility spectrum of the ion gate disclosed in fig. 1 operating at 20ppbv triethyl phosphate (TEP) with the Bradbury-Nielsen type ion gate conventional potential waveform was also obtained, as shown in fig. 5 c. Wherein, the signal intensity of the acetone dimer ion peak, the TEP monomer ion peak and the TEP dimer ion peak is respectively 134pA, 0pA and 0pA, and the resolution capability is respectively 60, 0 and 0. The TEP monomer and TEP dimer, which have ions with small mobility K, cannot be detected, and in addition, the signal intensity of the acetone dimer ion peak is reduced, and the resolution capability is also reduced.
Claims (10)
1. An ion gate for an ion mobility spectrometer, the ion mobility spectrometer comprising an ion mobility tube consisting of an ion source (1), an ionization region (2), an ion gate (3), a mobility region (4), and an ion receiving electrode (5) arranged in sequence along an ion mobility direction, characterized in that:
the ion gate (3) is composed of electrodes arranged in two planes which are parallel to each other and spaced by 1-5 mm, the plane close to the ionization region (2) is a first ion gate plane, the plane close to the migration region (4) is a second ion gate plane, and the first ion gate plane and the second ion gate plane are both vertical to the ion migration direction;
the electrode in the first ion gate plane is a strip electrode or an annular electrode; when the electrodes are strip-shaped electrodes, more than 4 even-numbered strip-shaped electrodes are arranged in parallel from top to bottom at intervals, the odd-numbered strip-shaped electrodes are used as first gate electrodes (3-1), and the even-numbered strip-shaped electrodes are used as second gate electrodes (3-2); or, when the electrode is a ring electrode, more than 4 ring electrodes which are even number and are concentric with the geometric center are arranged at intervals from inside to outside, the ring electrode with the odd number is used as a first gate electrode (3-1), and the ring electrode with the even number is used as a second gate electrode (3-2);
the electrode in the second ion gate plane is a strip electrode or an annular electrode; when the electrodes are strip electrodes, more than 4 strip electrodes with even numbers are arranged in parallel from top to bottom at intervals, the strip electrodes with the odd numbers are used as third gate electrodes (3-3), and the strip electrodes with the even numbers are used as fourth gate electrodes (3-4); or, when the electrodes are annular electrodes, more than 4 annular electrodes which are even number and are concentric with the geometric center are arranged at intervals from inside to outside, the odd number annular electrodes are used as third gate electrodes (3-3), and the even number annular electrodes are used as fourth gate electrodes (3-4);
the first gate electrode (3-1), the second gate electrode (3-2), the third gate electrode (3-3) and the fourth gate electrode (3-4) are insulated from each other.
2. The ion gate of claim 1, wherein: the strip-shaped electrode is a metal wire or a spiral linear electrode wound on a cylinder or a metal sheet or a metal mesh sheet;
the annular electrode is a circular ring electrode or a square ring electrode.
3. The ion gate of claim 1, wherein: the numbers of the first gate electrode (3-1), the second gate electrode (3-2), the third gate electrode (3-3) and the fourth gate electrode (3-4) are all equal.
4. The ion gate of claim 1, wherein: the first gate electrode (3-1), the second gate electrode (3-2), the third gate electrode (3-3) and the fourth gate electrode (3-4) are respectively connected with a direct current power supply.
5. The ion gate of claim 4, wherein: the direct current power supply is a pulse direct current high-voltage power supply.
6. An ion transfer tube comprising an ion gate as claimed in any one of claims 1 to 5.
7. An ion mobility spectrometer comprising the ion mobility tube of claim 6.
8. A method of controlling an ion gate according to any one of claims 1 to 5, wherein: at a first predetermined time interval t1A second predetermined time interval t2A third predetermined time interval t3Sequentially applying electric potential to the first gate electrode (3-1), the second gate electrode (3-2), the third gate electrode (3-3) and the fourth gate electrode (3-4);
at a first predetermined time interval t1In the first gate electrode (3-1) and the second gate electrode (3-2), a voltage V is applied simultaneously2A third gate electrode (3-3) applying a potential V1Fourth gate electrode (3-4) applying potential V3The ion gate (3) is opened at the first ion gate plane and closed at the second ion gate plane, and a uniform direct current electric field pointing to the ion gate (3) along the ion source (1) is formed in the ionization region (2), so that ions are emitted from the ionization regionA direct current electric field pointing to the direction of a second ion gate plane along a first ion gate plane is formed in the gate (3), and ions in the ionization region (2) enter the ion gate (3) through the first ion gate plane and are cut off at the second ion gate plane;
at a second predetermined time interval t2In which a first gate electrode (3-1) and a second gate electrode (3-2) are simultaneously applied with a potential V6The third gate electrode (3-3) and the fourth gate electrode (3-4) are simultaneously applied with a potential V1A direct current electric field pointing to the direction of an ion source (1) along an ion gate (3) is formed in an ionization region (2), ions in the ionization region (2) move towards the direction of the ion source (1), a uniform direct current electric field with unchanged direction and enhanced strength is formed in the ion gate (3), a uniform direct current electric field pointing to the direction of an ion receiving electrode (5) along the ion gate (3) is formed in a migration region (4), the electric field strength in the ion gate (3) is higher than that in the migration region (4), and ions existing between a first ion gate plane and a second ion gate plane are compressed through the second ion gate plane and are all injected into the migration region (4);
at a third predetermined time interval t3In the first gate electrode (3-1), a potential V is applied2The second gate electrode (3-2) applies a potential V4The third gate electrode (3-3) and the fourth gate electrode (3-4) are simultaneously applied with a potential V5The ion gate (3) is turned off at the first ion gate plane, a direct current electric field pointing to the ion gate (3) along the ion source (1) is formed in the ionization region (2), ions in the ionization region (2) are cut off at the first ion gate plane, a direct current electric field gradually weakened in the direction pointing to the ion receiving electrode (5) along the ion gate (3) is formed in the migration region (4), and the ions in the migration region (4) sequentially reach the ion receiving electrode (5) under the action of the direct current electric field to be detected;
potential V1、V2、V3、V4、V5And V6Are the same and the absolute values increase in sequence.
9. The control method according to claim 8, characterized in that: a first predetermined time interval t10.05-1 ms, a second preset time interval t20.005-0.2 ms, and a third predetermined time interval t3Is 1-10 ms.
10. The control method according to claim 8, characterized in that: at a first predetermined time interval t1A second predetermined time interval t2And a third predetermined time interval t3The summation of (a) constitutes a complete time period for the operation of the ion gate (3);
when the ion migration tube works, the potentials applied to the first gate electrode (3-1), the second gate electrode (3-2), the third gate electrode (3-3) and the fourth gate electrode (3-4) of the ion gate are periodically and circularly adjusted according to the time period.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113345791A (en) * | 2021-07-01 | 2021-09-03 | 中国科学院大连化学物理研究所 | Multi-switching pulse voltage waveform for ion mobility spectrometry |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109659219A (en) * | 2017-10-12 | 2019-04-19 | 中国科学院大连化学物理研究所 | A kind of the ion door gear and control method of no ion discrimination |
| CN110491765A (en) * | 2018-11-25 | 2019-11-22 | 中国科学院大连化学物理研究所 | A kind of control method of ion mobility spectrometry intermediate ion door |
| CN111199867A (en) * | 2018-11-20 | 2020-05-26 | 中国科学院大连化学物理研究所 | Low discrimination ion gate and control method |
| CN213988814U (en) * | 2020-11-17 | 2021-08-17 | 辽宁警察学院 | Ion gate for ion mobility spectrometer, ion mobility tube and ion mobility spectrometer |
-
2020
- 2020-11-17 CN CN202011286953.0A patent/CN112331550A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109659219A (en) * | 2017-10-12 | 2019-04-19 | 中国科学院大连化学物理研究所 | A kind of the ion door gear and control method of no ion discrimination |
| CN111199867A (en) * | 2018-11-20 | 2020-05-26 | 中国科学院大连化学物理研究所 | Low discrimination ion gate and control method |
| CN110491765A (en) * | 2018-11-25 | 2019-11-22 | 中国科学院大连化学物理研究所 | A kind of control method of ion mobility spectrometry intermediate ion door |
| CN213988814U (en) * | 2020-11-17 | 2021-08-17 | 辽宁警察学院 | Ion gate for ion mobility spectrometer, ion mobility tube and ion mobility spectrometer |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113345791A (en) * | 2021-07-01 | 2021-09-03 | 中国科学院大连化学物理研究所 | Multi-switching pulse voltage waveform for ion mobility spectrometry |
| CN113345791B (en) * | 2021-07-01 | 2023-07-25 | 中国科学院大连化学物理研究所 | Multi-switching pulse voltage waveform for ion mobility spectrometry |
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