Ion funnel trap control method

Abstract

The application discloses a novel ion funnel trap control method. In the injection enrichment stage, a lower intensity direct current electric field is applied in the storage area, ions entering the storage area are uniformly suspended and enriched along the axis, and the ion injection capacity is improved. In the shaping storage stage, a medium intensity direct current electric field is applied in the storage area, ions are compressed to the vicinity of the exit end grid, and the ion number density is improved. In the pulse release stage, a high intensity direct current electric field is applied in the storage area, ions quickly leave the storage area, and enter ion mobility spectrometry or mass spectrometry for separation and detection. The control of the internal electric field of the ion funnel trap can be realized through two potential modulation modes. One is to apply a periodically changing potential on the grids at the axial ends of the storage area of the ion funnel trap, so as to periodically change the electric field in the storage area. The other is to directly change the direct current electric field intensity in the storage area by periodically changing the potential difference between the resistance chains corresponding to the annular electrodes of the storage area.

Description

TECHNICAL FIELD

[0001] The present application relates to the control method of ion funnel trap, in particular to a method for improving the signal intensity of ion mobility spectrum by changing the electric field of ion funnel trap storage area. BACKGROUND

[0002] Ion funnel trap (IFT) is a sandglass-shaped electrodynamic ion funnel working at hundreds of pascal pressure, usually between ion source and ion mobility separation area or mass analyzer of low pressure ion mobility spectrometer or mass spectrometer, playing the role of ion transmission, storage and pulse injection. The large-diameter storage area of IFT can effectively accumulate ions between pulses, form pulse ion groups through ion gate injection technology, and then enter the mobility separation area for mobility separation under the action of electric field and supporting gas or enter the mass analyzer for detection. The release efficiency of IFT directly determines the signal intensity and detection sensitivity.

[0003] IFT was proposed in 2007 and is currently mainly used in Agilent's mobility spectrometer. IFT is stacked by metal electrodes with different inner diameters and insulating pads alternately, each electrode is divided by a series of resistors, and different voltage differences are applied in different areas to achieve the optimal ion transmission efficiency. Each electrode alternately applies 180° out-of-phase radio frequency potential, and the formed radio frequency electric field can bind ions in the radial direction and reduce diffusion loss. The middle area of IFT is the ion storage area, which is followed by a grid G1 in front of the storage area and a grid G2 and a grid G3 in turn.

[0004] In the conventional working mode of IFT, in a working cycle, in the injection stage, G1 applies the corresponding position voltage, G2 and G3 apply a voltage higher than the corresponding position voltage, and the ions move to the storage area under the action of the direct current electric field and accumulate; in the storage stage, G1, G2 and G3 all apply a voltage higher than the corresponding position voltage, the ions transmitted from the front stage are blocked by the reverse electric field formed by the high potential of G1, and the ions in the storage area will be bound in the area under the action of the radio frequency electric field; in the release stage, the voltage of G1 is the same as that in the storage stage, G2 and G3 apply the corresponding position voltage, and the ions leave the storage area under the action of the electric field.

[0005] The ion release efficiency of IFT is directly related to the distribution of ion groups in the storage area before release and the electric field of the storage area in the release stage. In order to accumulate more ions in the storage area of IFT, the electric field intensity of the area is usually low, so in the release stage, if only the direct current electric field of the storage area itself is used to drive ions, the ions that can be released are also less, and the ions with smaller mobility have lower release efficiency due to slow movement speed, causing serious mobility discrimination. Ibrahim et al. (Anal. Chem., 2007, 79: 7845-7852) applied a higher potential than the position potential to G1 to drive the release of ions in the release stage. This ion gate control method has limited effect on signal enhancement for a relatively narrow release time (<40 μs), and the release efficiency of small mobility ions is also poor. In order to improve the release efficiency of IFT for small mobility ions, Ibrahim et al. (Anal. Chem, 2014, 86: 5295-5299) used helium instead of nitrogen as the floating gas, which improved the signal intensity by 10 times. The essential reason is that the mobility of ions in helium is larger, so the ions can be released faster and more efficiently. Gabelica et al. (J. Am. Soc. Mass Spectrom., 2018, 29: 2189-2198) reported that by increasing the electric field intensity of the ion funnel trap storage area, adjusting the ion gate closing voltage and optimizing the radio frequency amplitude to reduce ion fragmentation, the optimal conditions for performing 10 kDa complex collision-induced experiments were explored.

[0006] At present, the ion funnel trap still has the problem of low ion release rate, especially low release rate of small mobility ions, resulting in low signal intensity under narrow release time. SUMMARY

[0007] In order to solve the problem of low release efficiency of ion funnel trap under narrow opening time, resulting in low signal intensity, the present application discloses a control method of ion funnel trap, which periodically changes the grid voltage of ion funnel trap or periodically changes the potential difference between the two ends of the resistance chain corresponding to the annular electrode of the storage area, so as to periodically change the electric field of the storage area of the ion funnel trap, thereby realizing the injection enrichment, storage shaping and pulse release of ions.

[0008] The technical scheme adopted by the present application to achieve the above-mentioned purpose is:

[0009] The application relates to a kind of ion funnel trap control method, the ion funnel trap is made of 96 annular metal electrodes with the inner diameter of hourglass-shaped change in coaxial, equal interval mode stack;Along the axis from left to right, the first electrode to the 63rd electrode of ion funnel trap constitutes ion introduction area, between the 64th electrode and the 75th electrode constitutes ion storage area, between the 76th electrode and the 96th electrode constitutes ion lead-out area;Wherein, the inside of the 64th electrode, the 75th electrode, the 76th electrode is provided with the metal grid that can be permeated by ion, except the 64th electrode, the 75th electrode and the 76th electrode, the first electrode to the 96th electrode of ion funnel trap is connected with power supply by voltage dividing resistor chain, to form the direct current electric field of same ion migration direction in the ion introduction area, ion storage area and ion lead-out area of ion funnel trap respectively;

[0010] In the working cycle of ion funnel trap, the electric field intensity of ion introduction area and ion lead-out area is maintained E1 and E3 respectively, the potential of the resistor chain position corresponding to the 64th electrode, the 75th electrode and the 76th electrode is V G1 , V G2 And V G3 , wherein V G1 >V G2 >V G3 ;

[0011] In the working cycle of ion funnel trap, the electric field intensity of ion storage area is controlled to increase with time, at timing moment t0≤t

[0012] At timing moment t1≤t

[0013] At timing moment t2≤t

[0014] The periodic change of ion storage area electric field is realized by modulating the potential of the 64th electrode, specifically:

[0015] At timing moment t0≤t G1Electrodes 75 and 76 are respectively applied with a potential V corresponding to their respective positions. G2 and V G3 Higher potentials V2 and V3, V3>V2>V G2 >V G3 ;

[0016] At timing t1≤t<t2, the electric field strength formed by the potential difference between the two ends of the corresponding resistive chain in the ion storage region is E2. The sixty-fourth electrode applies a potential V that is higher than the potential at the corresponding position. 11 V 11 >V G1 Potentials V2 and V3 are applied to the seventy-fifth and seventy-sixth electrodes, respectively;

[0017] At timing t2≤t<t3, the electric field intensity E2 is formed by the potential difference between the two ends of the corresponding resistive chain in the ion storage region. A higher voltage V is applied to the sixty-fourth electrode. 12 V 12 >V 11 Electrodes 75 and 76 are respectively applied with corresponding position potentials V. G2 and V G3 .

[0018] The periodic variation of the electric field in the ion storage region is achieved by modulating the electric field strength formed by the potential difference between the two ends of the corresponding resistive chain in the ion storage region. Specifically:

[0019] At timing t0 ≤ t < t1, the electric field strength formed by the potential difference between the two ends of the corresponding resistive chain in the ion storage region is E2, and the corresponding position potential V is applied to the sixty-fourth electrode. G1 Electrodes 75 and 76 are respectively applied with a potential V corresponding to their respective positions. G2 and V G3 Higher potentials V2 and V3, V3>V2>V G2 >V G3 ;

[0020] At timing t1≤t<t2, the electric field strength formed by the potential difference between the two ends of the corresponding resistive chain in the ion storage region is E2. The sixty-fourth electrode applies a potential V that is higher than the potential at the corresponding position. 11 V 11 >V G1 Potentials V2 and V3 are applied to the seventy-fifth and seventy-sixth electrodes, respectively;

[0021] At timing t2≤t<t3, the electric field strength formed by the potential difference between the two ends of the corresponding resistive chain in the ion storage region is E2', E2'>E2, and the potential V applied to the sixty-fourth electrode is V. 11 Electrodes 75 and 76 are respectively applied with corresponding position potentials V. G2And V G3 .

[0022] The difference between the timing moment t3 and t0 is the ion gate working period T, which is 30-100 ms, the difference between the timing moment t1 and t0 is defined as the injection time, the difference between the timing moment t2 and t1 is defined as the storage time, which is 0-1000 μs, and the difference between the timing moment t3 and t2 is defined as the release time, which is 10-100 μs.

[0023] When the ion funnel trap works, the electric potential applied by the sixty-fourth electrode, the seventy-fifth electrode and the seventy-sixth electrode or the electric field strength formed by the potential difference between the two ends of the ion storage area corresponding resistor chain is periodically and cyclically adjusted in time sequence.

[0024] The present application has the following advantages and benefits:

[0025] 1. The present application realizes the injection enrichment, storage shaping and efficient release of ions by periodically changing the electric field of the storage area. In the injection stage, the electric field strength of the storage area is low, which is beneficial to the enrichment of ions; in the storage stage, the electric field of the storage area is increased by increasing the potential of the inlet end grid of the storage area, and the ion group is compressed towards the outlet end grid; in the release stage, the electric field of the storage area is further increased by increasing the potential of the inlet end grid or increasing the direct current electric field strength of the storage area, so as to accelerate the ion movement speed, thereby improving the ion release efficiency of the ion funnel trap.

[0026] 2. The present application improves the percentage of ions entering the subsequent stage from the storage area in the release stage by increasing the ion number density in front of the outlet end grid before release and the electric field strength of the storage area during release, and the release effect of ions with different mobilities is also improved, thereby improving the signal strength and detection sensitivity of the ion mobility spectrum. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a schematic diagram of the ion funnel trap structure adopting the control method disclosed by the present application.

[0028] Figure 2 It is a voltage schematic diagram of the ion funnel trap electrodes in different stages under the conventional working mode.

[0029] Figure 3 It is a voltage schematic diagram of the ion funnel trap electrodes in different stages under the working mode of the present application, in which the electric field of the storage area is periodically changed by modulating the potential of the grid.

[0030] Figure 4 It is a voltage schematic diagram of the ion funnel trap electrodes in different stages under the working mode of the present application, in which the electric field of the storage area is periodically changed by modulating the potential difference between the two ends of the resistor chain corresponding to the storage area.

[0031] Figure 5Fig. 64 is a schematic diagram of ion distribution in the storage region after (a) 0 μs, (b) 100 μs, (c) 200 μs in the SIMION simulation when the gate voltage of the 64th electrode is 15 V in the storage stage.

[0032] Figure 6 Fig. 65 is a schematic diagram of the relationship between the number of released ions and the storage time in the SIMION simulation when the gate voltage of the 64th electrode is 15 V in the storage stage.

[0033] Figure 7 Fig. 66 is a schematic diagram of the relationship between the number of released ions and the electric field intensity of the storage region in the release stage in the SIMION simulation.

[0034] Figure 8 Fig. 67 is a mass spectrum when the release time is 30 μs and the storage time is from 0 to 400 μs in the acetone assisted triethyl phosphate photoionization.

[0035] Figure 9 Fig. 68 is a mass spectrum when the release time is 50 μs and the storage time is from 0 to 400 μs in the acetone assisted triethyl phosphate photoionization. DETAILED DESCRIPTION

[0036] The application will be further described in detail below with reference to the accompanying drawings and examples.

[0037] A control method of an ion funnel trap. The ion funnel trap is formed by alternately stacking 96 annular metal electrodes with different inner diameters and ceramic spacers, and the thickness of the electrodes is 0.5 mm and the spacing between the electrodes is 0.5 mm. The ion funnel trap is divided into three regions: the first to the 63rd annular electrodes constitute an ion introduction region, the inner diameter gradually decreases from 24 mm to 3 mm and then increases to 20 mm; the 64th to the 75th annular electrodes constitute an ion storage region, the inner diameter is 20 mm; the 76th to the 96th annular electrodes constitute an ion extraction region, the inner diameter gradually decreases from 20 mm to 3 mm. The 64th electrode, the 75th electrode and the 76th electrode are sequentially provided with metal mesh grids that are permeable to ions.

[0038] Except for the electrodes where the mesh grids are located, the remaining annular electrodes are electrically connected to a power supply through a voltage dividing resistor chain, thereby forming a direct current electric field in the ion introduction region, the ion storage region and the ion extraction region of the ion funnel trap, which is the same as the direction of ion migration. The potential at the positions corresponding to the 64th electrode, the 75th electrode and the 76th electrode is V G1 , V G2 and V G3 , respectively, and V G1 >V G2 >V G3During the working cycle of the ion funnel trap, the DC electric field strengths in the ion introduction region and the ion extraction region of the ion funnel trap are maintained at E1 and E3, respectively. The electric field in the ion storage region changes periodically by modulating the grid potential or the potential difference between the two ends of the corresponding resistor chain in the storage region.

[0039] At the timing t0≤t<t1, i.e., the injection enrichment stage, the DC electric field strength formed by the potential difference between the two ends of the resistor chain corresponding to the storage region is E2, and the corresponding position potential V is applied to the sixty-fourth electrode. G1 Electrodes 75 and 76 are respectively applied with a potential V corresponding to their respective positions. G2 and V G3 Higher potentials V2 and V3 (V3>V2>V) G2 >V G3 The ion stream transported from the ion introduction region fills the ion storage region.

[0040] At the timing t1≤t<t2, i.e. the storage shaping stage, the DC electric field strength formed by the potential difference between the two ends of the resistor chain corresponding to the storage region is E2. The sixty-fourth electrode is applied with a potential V higher than the potential at the corresponding position. 11 (V 11 >V G1 Potentials V2 and V3 are applied to electrodes 75 and 76, respectively. The ion flow transported from the ion introduction region will be blocked by the reverse electric field formed by the high potential of electrode 64, while the ions that have already entered the storage region will move towards electrode 75 under the action of the forward electric field formed by the high potential of electrode 64. At the same time, due to the reverse electric field formed by the high voltage of electrodes 75 and 76, they will not be annihilated onto the grid.

[0041] At timing t2≤t<t3, i.e., the pulse release phase, in the control method that periodically changes the electric field of the storage region by modulating the grid potential, the DC electric field strength formed by the potential difference at both ends of the corresponding resistor chain in the storage region is still E2, and a higher potential V is applied to the sixty-fourth electrode. 12 (V 12 >V 11 Electrodes 75 and 76 are respectively applied with corresponding position potentials V. G2 and V G3 The ion clusters in the storage region will accelerate into the ion extraction region under the influence of the positive electric field formed by the high potential of the sixty-fourth electrode. In the control method of periodically changing the electric field of the storage region by modulating the potential difference between the two ends of the corresponding resistor chain, the DC electric field strength formed by the potential difference between the two ends of the corresponding resistor chain is E2' (E2'>E2), and the potential of the sixty-fourth electrode remains V. 11 Electrodes 75 and 76 are respectively applied with corresponding position potentials V. G2 and V G3The ion groups in the storage area will be accelerated into the ion extraction area under the action of a higher direct current electric field.

[0042] The difference between the timing moment t3 and t0 is the ion funnel trap working period T, which is 30-100 ms.

[0043] When the ion funnel trap is working, the electric potential applied to the grid and the direct current electric field strength formed by the potential difference between the two ends of the resistance chain in the storage area are periodically and cyclically regulated according to the timing sequence.

[0044] The ion funnel trap adopting the working mode disclosed in the application is composed of Figure 1 as shown in the figure, which is formed by alternately stacking annular metal electrodes and ceramic gaskets with different inner diameters, wherein: 1-96, annular metal electrodes; 97, ion introduction area; 98, ion storage area; 99, ion extraction area, the electrode thickness is 0.5 mm, and the electrode spacing is 0.5 mm. The ion funnel trap is divided into three areas: the ion introduction area from the first electrode to the sixty-third electrode, the ion storage area between the sixty-fourth electrode and the seventy-fifth electrode, and the ion extraction area from the seventy-sixth electrode to the ninety-sixth electrode. The interiors of the sixty-fourth electrode, the seventy-fifth electrode and the seventy-sixth electrode are all provided with metal grid.

[0045] Figure 2 The voltages of each electrode at different stages in the conventional working mode are shown, and in the entire working cycle, the direct current electric field strengths of the ion introduction area, the ion storage area and the ion extraction area of the ion funnel trap are respectively maintained at E1, E2 and E3 unchanged, the sixty-fourth electrode applies the corresponding position voltage in the injection stage, and applies the same size of gate voltage in the storage and release stages; the seventy-fifth electrode and the seventy-sixth electrode apply the corresponding gate voltage in the injection and storage stages, and apply the corresponding position voltage in the release stage.

[0046] Figure 3 The voltages of each electrode at different stages in the working mode disclosed in the application are shown, and in the entire working cycle, the direct current electric field strengths of the ion introduction area, the ion storage area and the ion extraction area of the ion funnel trap are respectively maintained at E1, E2 and E3 unchanged, the sixty-fourth electrode applies the corresponding position voltage in the injection stage, and applies one low and one high two different gate voltages in the storage and release stages respectively; the seventy-fifth electrode and the seventy-sixth electrode apply the corresponding gate voltage in the injection and storage stages, and apply the corresponding position voltage in the release stage.

[0047] Figure 4The voltage of each electrode at different stages in the working mode of changing the electric field of the storage region by changing the direct current electric field strength of the storage region is shown. In the entire working cycle, the direct current electric field strength of the ion introduction area and the ion extraction area of the ion funnel trap is maintained at E1 and E3, respectively, the direct current electric field strength of the ion storage area is maintained at E2 in the injection and storage stages, and is increased to E2' (E2'>E2) in the release stage. The sixty-fourth electrode applies the corresponding position voltage in the injection stage, and applies the same gate-off voltage in the storage and release stages. The seventy-fifth electrode and the seventy-sixth electrode apply the corresponding gate-off voltage in the injection and storage stages, and apply the corresponding position voltage in the release stage.

[0048] In order to illustrate the influence of the control mode disclosed by the application on the distribution of ions before release in the storage region, an ion funnel trap model is established in ion optical simulation software SIMION, and the voltage applied to each electrode is changed periodically by writing lua code. Figure 3 The basic parameters are that the electric field strength of the ion introduction area is 10 V / cm, the electric field strength of the ion storage area is 2 V / cm, the electric field strength of the ion storage area is 20 V / cm, the release voltage of the sixty-fourth electrode is 50 V, and the gate-off voltages of the seventy-fifth electrode and the seventy-sixth electrode are 2.5 V and 5 V, respectively. Figure 5 When the storage voltage of the sixty-fourth electrode is 15 V, the ion distribution in the storage region of the ion funnel trap is shown when the storage time is 0, 100 and 200 μs. With the extension of the storage time, the center position of the ion group gradually approaches the seventy-fifth electrode, and the distribution gradually narrows. The release time is set to 50 μs, and the release number of different m / z ions is counted for 1000 times (Fig. 6) Figure 6 ), and the release number of each m / z ion is improved, and the effect of m / z=622 ion is the most significant.

[0049] Due to the limitation of the circuit, the test of changing the electric field of the storage region by periodically changing the potential difference between the two ends of the resistance chain in the storage region is not carried out, but the simulation is carried out in SIMION, and the influence of the increase of the direct current electric field of the storage region in the release stage on the ion release efficiency is explored. The storage time is set to 0 μs, the release time is set to 50 μs, the electric field strength of the storage region in the injection and storage stages is set to 2 V / cm, and the relationship between the release number of each m / z ion and the electric field strength of the storage region in the release stage is obtained (Fig. 7) Figure 7 ). When the electric field strength of the storage region in the release stage is increased from 2 V / cm to 10 V / cm, the release number of m / z=80 and 322 ions is increased by 159% and 95%, respectively. The simulation result shows that the control method proposed in the application has theoretical and simulation basis, but due to the limitation of the actual circuit condition, the test is not carried out.

[0050] Embodiment

[0051] The voltage-dividing resistor chain of the ion funnel trap is composed of the same number of voltage-dividing resistors connected in series from left to right, matching the number of ring electrodes. The two ends of the resistor chain and the connection points between adjacent resistors are electrical connection points. A DC isolation power supply provides a 50V potential difference between the resistor chain positions corresponding to the first electrode and the sixty-fourth electrode; a DC isolation power supply provides a 1.1V potential difference between the resistor chain positions corresponding to the sixty-fourth and seventy-fifth electrodes; and a DC isolation power supply provides a 50V potential difference between the resistor chain positions corresponding to the seventy-fifth and ninety-sixth electrodes. This creates a gradually decreasing potential distribution along the ion flow direction, resulting in DC electric field strengths of 7.8V / cm, 1V / cm, and 22.7V / cm in the ion introduction, storage, and extraction regions of the ion funnel trap, respectively. Taking the potential at the end of the series resistor chain of the ion funnel trap as the zero potential point, the voltage at the position corresponding to the sixty-fourth electrode is 51.1V, the voltage at the position corresponding to the seventy-fifth electrode is 50V, and the voltage at the position corresponding to the seventy-sixth electrode is 47.7V.

[0052] according to Figure 3 The applied voltages are as follows: for the sixty-fourth electrode, the voltages during the injection, storage, and release phases are 51.1V, 66.1V, and 81.5V, respectively; for the seventy-fifth electrode, the voltages during the injection, storage, and release phases are 51.6V, 51.6V, and 50V, respectively; and for the seventy-sixth electrode, the voltages during the injection, storage, and release phases are 52.5V, 52.5V, and 47.7V, respectively.

[0053] The ion funnel trap, serving as the ion transport device in the ion mobility spectrum platform, releases ion clusters that, after entering the migration region, undergo mobility separation under the influence of an electric field and supporting gas before reaching the electron multiplier. The weak current signal is then converted into a voltage signal by a current amplifier and amplified. Waveform data is acquired using an oscilloscope and processed to obtain the ion mobility spectrum. The ion funnel trap operates at a pressure of 540 Pa, a temperature of 298 K, and an RF voltage frequency of 0.98 MHz with a peak-to-peak voltage of 200 V. The ion funnel trap's working period is set to 50 ms, the release time to 30 μs, and the migration spectrum of acetone-assisted triethyl phosphate photoionization is recorded over storage times ranging from 0 to 400 μs. Figure 8 The results showed that as the storage time increased from 0 to 400 μs, the equivalent migration mobility was 1.52, 1.42, and 1.23 cm⁻¹, respectively. 2 V -1 s -1The peak heights of the ions are increased from 20 mV, 18 mV and 112 mV to 124 mV, 136 mV and 684 mV, respectively, which are 6.2, 7.5 and 6.1 times of the original peak heights, respectively. When the ion funnel trap working period is set to 50 ms, the release time is 50 μs, and the recording storage time is 0-400 μs, the acetone-assisted triethyl phosphate photoionization mobility spectrum changes with the storage time (Fig. 18), Figure 9 ), and the results show that, as the storage time increases from 0 to 400 μs, the equivalent mobility of the ions is 1.52, 1.42 and 1.23 cm 2 V -1 s -1 The peak heights of the ions are increased from 40 mV, 32 mV and 284 mV to 168 mV, 168 mV and 928 mV, respectively, which are 4.2, 5.2 and 3.3 times of the original peak heights, respectively. Obviously, using the control method disclosed in the present application, Figure 3 ), the signal intensity of each mobility ion with a narrow release time (≤50 μs) can be significantly improved, and the smaller the release time, the higher the improvement multiple.

Claims

1. A method for controlling an ion funnel trap, the ion funnel trap being composed of 96 annular metal electrodes with inner diameter changing in a shape of a sandglass, stacked coaxially and equidistantly; along the axis from left to right, the ion funnel trap is composed of a first electrode (1) to a 63rd electrode (63) to form an ion introduction zone (97), a 64th electrode (64) to a 75th electrode (75) to form an ion storage zone (98), and a 76th electrode (76) to a 96th electrode (96) to form an ion extraction zone (99); wherein, The sixth electrode (64), the seventy-fifth electrode (75), and the seventy-sixth electrode (76) are internally provided with ion-permeable metal grids. In addition to the sixth electrode (64), the seventy-fifth electrode (75), and the seventy-sixth electrode (76), the first electrode (1) to the ninety-sixth electrode (96) of the ion funnel trap are electrically connected to a power supply through a voltage dividing resistor chain, and a direct current electric field in the same direction as the ion migration direction is formed in the ion introduction area (97), the ion storage area (98), and the ion extraction area (99) of the ion funnel trap. In the working cycle of the ion funnel trap, the electric field strengths of the ion introduction region (97) and the ion extraction region (99) are maintained as E1 and E3 respectively unchanged, the potential of the corresponding resistance chain positions of the sixty-fourth electrode (64), the seventy-fifth electrode (75) and the seventy-sixth electrode (76) are V G1 , V G2 and V G3 respectively, wherein V G1 >V G2 >V G3 . During the working period of the ion funnel trap, the electric field intensity of the ion storage area (98) is controlled to increase with time. At the timing moment t0≤t At the timing moment t1≤t At the timing moment t2≤t The periodic change of the electric field of the ion storage area (98) is realized by modulating the electric potential of the sixth electrode (64), and the specific method is as follows: At timing t0≤t<t1, the electric field strength formed by the potential difference between the two ends of the resistance chain corresponding to the ion storage region (98) is E2, the sixth-fourth electrode (64) applies the corresponding position potential V G1 , the seventy-fifth electrode (75) and the seventy-sixth electrode (76) apply higher potentials V G2 and V G3 respectively, V3>V2>V G2 >V G3 ; At a time t1≤t<t2, the electric field strength formed by the potential difference between the two ends of the corresponding resistance chain of the ion storage region (98) is E2, the sixty-fourth electrode (64) applies a potential V 11 , V 11 >V G1 , the seventy-fifth electrode (75) and the seventy-sixth electrode (76) apply potentials V2 and V3, respectively; At a time t2≤t<t3, the electric field strength E2 formed by the potential difference between the two ends of the resistance chain corresponding to the ion storage region (98) is higher than E1, and the sixty-fourth electrode (64) applies a higher voltage V 12 , 12 , 11 , The seventy-fifth electrode (75) and the seventy-sixth electrode (76) apply corresponding position potentials V G2 and V G3 , respectively.

2. A method for controlling an ion funnel trap, the ion funnel trap being composed of 96 annular metal electrodes with inner diameters changing in a shape of a sandglass, stacked coaxially and equidistantly; along the axial direction from left to right, the ion funnel trap is composed of a first electrode (1) to a 63rd electrode (63) to form an ion introduction zone (97), a 64th electrode (64) to a 75th electrode (75) to form an ion storage zone (98), and a 76th electrode (76) to a 96th electrode (96) to form an ion extraction zone (99); wherein, The sixth electrode (64), the seventy-fifth electrode (75), and the seventy-sixth electrode (76) are internally provided with ion-permeable metal grids. In addition to the sixth electrode (64), the seventy-fifth electrode (75), and the seventy-sixth electrode (76), the first electrode (1) to the ninety-sixth electrode (96) of the ion funnel trap are electrically connected to a power supply through a voltage dividing resistor chain, and a direct current electric field in the same direction as the ion migration direction is formed in the ion introduction area (97), the ion storage area (98), and the ion extraction area (99) of the ion funnel trap. In the working cycle of the ion funnel trap, the electric field strengths of the ion introduction zone (97) and the ion extraction zone (99) are maintained as E1 and E3 respectively unchanged, the potential of the corresponding resistance chain positions of the sixty-fourth electrode (64), the seventy-fifth electrode (75) and the seventy-sixth electrode (76) are V G1 , V G2 and V G3 respectively, wherein V G1 >V G2 >V G3 ; During the working period of the ion funnel trap, the electric field intensity of the ion storage area (98) is controlled to increase with time. At the timing moment t0≤t At the timing moment t1≤t At the timing moment t2≤t At timing moment t2≤t<t3, due to the high electric field intensity of the ion storage region (98), the ions are accelerated to move through the seventy-fifth electrode (75) and the seventy-sixth electrode (76) into the ion extraction region (99) under the action of the high electric field of the ion storage region (98), and are further transmitted to a migration spectrum or a mass spectrum for separation and detection, and this stage is taken as a pulse release stage; The electric field intensity of the ion storage region (98) is periodically changed by modulating the electric field intensity formed by the potential difference between the two ends of the corresponding resistance chain of the ion storage region (98), and specifically: At the timing t0≤t<t1, the electric field strength formed by the potential difference between the two ends of the resistor chain corresponding to the ion storage region (98) is E2, and the corresponding position potential V is applied to the sixty-fourth electrode (64). G1 The seventy-fifth electrode (75) and the seventy-sixth electrode (76) are respectively applied with a potential V that is greater than the corresponding position. G2 and V G3 Higher potentials V2 and V3, V3>V2>V G2 >V G3 ; At a time t1≤t<t2, the electric field strength formed by the potential difference between the two ends of the corresponding resistance chain of the ion storage region (98) is E2, the sixty-fourth electrode (64) applies a potential V 11 , V 11 > V G1 , the seventy-fifth electrode (75) and the seventy-sixth electrode (76) apply potentials V2 and V3 respectively; At timing t2≤t<t3, the electric field strength formed by the potential difference between the two ends of the corresponding resistance chain of the ion storage region (98) is E2', E2'>E2, the sixth-fourth electrode (64) applies a potential V 11 , the seventy-fifth electrode (75) and the seventy-sixth electrode (76) apply corresponding position potentials V G2 and V G3 , respectively.

3. The ion funnel-trap control method according to claim 1 or 2, wherein, The difference between the timing moment t3 and t0 is the ion gate working period T, which is 30-100 ms, the difference between the timing moment t1 and t0 is defined as the injection time, and the difference between the timing moment t2 and t1 is defined as the storage time, which is 0-1000 μs, and the difference between the timing moment t3 and t2 is defined as the release time, which is 10-100 μs.

4. The ion funnel-trap control method according to claim 1 or 2, wherein When the ion funnel trap works, the electric potential applied by the sixty-fourth electrode (64), the seventy-fifth electrode (75) and the seventy-sixth electrode (76) or the electric field intensity formed by the potential difference between the two ends of the corresponding resistance chain of the ion storage region (98) is periodically and cyclically adjusted in time sequence.

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