Control method for ion funnel trap
Patent Information
- Application Number
- PCT/CN2025/078372
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-02-18
- Filing Date
- 2025-02-21
- Publication Date
- 2026-08-27
Smart Images
Figure CN2025078372_27082026_PF_FP_ABST
Abstract
Description
A method for controlling an ion funnel trap Technical Field
[0001] This invention relates to a control method for an ion funnel trap, specifically a method for increasing the intensity of a migration spectrum signal by changing the electric field in the storage region of an ion funnel trap. Background Technology
[0002] An ion funnel trap (IFT) is an hourglass-shaped electrically driven ion funnel operating at hectopascals (HPa). It is typically positioned between the ion source and the migration region or mass analyzer in a low-pressure ion mobility spectrometer or mass spectrometer, serving to transport, store, and pulse-inject ions. The relatively large inner diameter of the IFT's storage region allows for effective ion accumulation between pulses. Through ion-gated injection technology, pulsed ion clusters are formed, which then enter the migration region where, under the influence of an electric field and supporting gas, they undergo mobility separation or are detected by the mass analyzer. The release efficiency of the IFT directly determines the signal strength and detection sensitivity.
[0003] IFT (Integrated Wave Transfer) was proposed in 2007 and is currently mainly used in Agilent Technologies' mobility mass spectrometers. IFT consists of alternating stacks of metal electrodes with different inner diameters and insulating pads. Each electrode is connected by a series resistor chain to divide the voltage, and different voltage differences are applied in different regions to achieve optimal ion transport efficiency. Alternating 180° out-of-phase radio frequency potentials are applied to each electrode, and the resulting radio frequency electric field can radially confine ions, reducing diffusion losses. The central region of the IFT is the ion storage region, preceded by a grid G1, followed by grids G2 and G3.
[0004] In the normal operating mode of IFT, during one working cycle, during the injection phase, G1 applies the corresponding position voltage, while G2 and G3 apply voltages higher than the corresponding position voltages. Ions move to the storage area and accumulate under the influence of the DC electric field. During the storage phase, G1, G2, and G3 all apply voltages higher than the corresponding position voltages. Ions transferred from the previous stage are blocked by the reverse electric field formed by the high potential of G1, and the ions in the storage area are bound to the area under the influence of the radio frequency electric field. During the release phase, the voltage of G1 is the same as in the storage phase, while G2 and G3 apply the corresponding position voltages, and ions leave the storage area driven by the electric field.
[0005] The ion release efficiency of IFT is directly related to the distribution of ion clusters in the storage region before release and the electric field in the storage region during the release phase. To accumulate more ions in the IFT storage region, the electric field strength in this region is typically low. Therefore, during the release phase, if only the DC electric field of the storage region itself is used to drive the ions, fewer ions can be released. Ions with lower mobility have slower movement speeds, resulting in even lower release efficiency and severe mobility discrimination. Ibrahim et al. (Anal. Chem., 2007, 79: 7845-7852) applied a potential higher than the position potential to G1 during the release phase to drive ion release. This ion-gating control method has limited signal enhancement effects for narrow release times (<40 μs), and the release efficiency of ions with low mobility is also poor. To improve the release efficiency of IFT for low-mobility ions, Ibrahim et al. (Anal. Chem, 2014, 86: 5295-5299) used helium instead of nitrogen as the drift gas, resulting in a 10-fold increase in signal intensity. This is because ions have greater mobility in helium, allowing for faster and more efficient ion release. Gabelica et al. (J. Am. Soc. Mass Spectrom., 2018, 29: 2189-2198) reported that by increasing the electric field strength in the ion funnel trap storage region, adjusting the ion gate closing voltage, and optimizing the radio frequency amplitude to reduce ion fragmentation, they explored optimal conditions for performing collision-induced experiments on 10 kDa complexes.
[0006] Currently, ion funnel traps still suffer from low ion release rates, especially low release rates of low-mobility ions, leading to low signal strength under narrow release times. Summary of the Invention
[0007] To address the problem of low release efficiency and resulting low signal strength in ion funnel traps under narrow gate times, this invention discloses a control method for ion funnel traps. By periodically changing the grid voltage of the ion funnel trap or periodically changing the potential difference between the two ends of the resistor chain corresponding to the annular electrode in the storage region, the electric field in the storage region of the ion funnel trap changes periodically, thereby realizing ion implantation enrichment, storage shaping, and pulse release.
[0008] The technical solution adopted by the present invention to achieve the above objectives is as follows:
[0009] An ion funnel trap control method is disclosed, wherein the ion funnel trap is composed of ninety-six annular metal electrodes with varying inner diameters in an hourglass shape, stacked coaxially and at equal intervals; along the axial direction from left to right, the first to sixty-third electrodes of the ion funnel trap form an ion introduction region, the sixty-fourth to seventy-fifth electrodes form an ion storage region, and the seventy-sixth to ninety-sixth electrodes form an ion extraction region; wherein the interior of the sixty-fourth, seventy-fifth, and seventy-sixth electrodes is provided with a permeable metal grid; except for the sixty-fourth, seventy-fifth, and seventy-sixth electrodes, the first to ninety-sixth electrodes of the ion funnel trap are electrically connected to a power supply through a voltage divider resistor chain, thereby forming a DC electric field in the ion introduction region, ion storage region, and ion extraction region of the ion funnel trap, respectively, in the same direction as the ion migration.
[0010] During the working cycle of the ion funnel trap, the electric field strengths in the ion introduction and ion extraction regions remain constant at E1 and E3, respectively. The potentials at the resistive chain positions corresponding to the sixty-fourth, seventy-fifth, and seventy-sixth electrodes are V, respectively. G1 V G2 and V G3 , where V G1 >V G2 >V G3 ;
[0011] During the working cycle of the ion funnel trap, the electric field strength of the ion storage region is increased with time. At the timing t0≤t<t1, since the electric field strength of the ion storage region is low, ions pass through the sixty-fourth electrode from the ion introduction region into the ion storage region and are suspended and enriched along the axis of the ion funnel trap. This stage is called the injection enrichment stage.
[0012] At the timing t1≤t<t2, since the electric field strength in the ion storage region is moderate, the electric field drives the ions to move toward the seventy-fifth electrode, and the ion number density in front of the seventy-fifth electrode increases. This stage is regarded as the storage shaping stage.
[0013] At the timing t2≤t<t3, due to the high electric field strength in the ion storage region, the ions accelerate under the influence of the high electric field in the ion storage region, pass through the seventy-fifth and seventy-sixth electrodes and enter the ion extraction region, and are further transported to the mobility spectrum or mass spectrometer for separation and detection. This stage is referred to as the pulse release stage.
[0014] The periodic change of the electric field in the ion storage region is achieved by modulating the potential of the sixty-fourth electrode, specifically as follows:
[0015] 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. 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 timing t3 and t0 is the ion gate working period T, which is 30 to 100 ms. The difference between timing t1 and t0 is defined as the injection time. The difference between timing t2 and t1 is defined as the storage time, which is 0 to 1000 μs. The difference between timing t3 and t2 is defined as the release time, which is 10 to 100 μs.
[0023] When the ion funnel trap is in operation, the electric field strength formed by the potential applied to the sixty-fourth, seventy-fifth and seventy-sixth electrodes or the potential difference between the two ends of the corresponding resistive chain in the ion storage region is periodically cyclically adjusted according to the time sequence.
[0024] The present invention has the following beneficial effects and advantages:
[0025] 1. This invention achieves ion implantation enrichment, storage shaping, and efficient release by periodically changing the electric field of the storage region. During the implantation stage, the electric field strength of the storage region is relatively low, which is conducive to ion enrichment. During the storage stage, the electric field of the storage region is increased by raising the grid potential at the entrance end of the storage region, causing ion clusters to be compressed towards the grid at the exit end. During the release stage, the electric field of the storage region is further increased by raising the grid potential at the entrance end or by increasing the DC electric field strength of the storage region, accelerating the ion movement speed, thereby improving the ion release efficiency of the ion funnel trap.
[0026] 2. This invention increases the percentage of ions entering the subsequent stage from the storage region by increasing the ion number density before the gate at the outlet end before release and the electric field strength in the storage region during release. It also improves the release effect for ions with different mobility, thereby increasing the signal strength and detection sensitivity of the ion mobility spectrum. Attached Figure Description
[0027] Figure 1 is a schematic diagram of an ion funnel trap structure using the control method disclosed in this invention.
[0028] Figure 2 is a schematic diagram of the voltage of each electrode of the ion funnel trap at different stages under normal operating mode.
[0029] Figure 3 is a schematic diagram of the voltage of each electrode of the ion funnel trap at different stages under the working mode of controlling the periodic change of the electric field in the storage area by modulating the grid potential as disclosed in this invention.
[0030] Figure 4 is a schematic diagram of the voltage of each electrode of the ion funnel trap at different stages under the working mode disclosed in this invention, which controls the periodic change of the electric field in the storage area by modulating the potential difference between the two ends of the corresponding resistor chain in the storage area.
[0031] Figure 5 shows the ion distribution in the storage region after (a) 0 μs, (b) 100 μs, and (c) 200 μs storage when the gate voltage of the 64th electrode is 15V during the storage stage in SIMION simulation.
[0032] Figure 6 shows the relationship between the number of ions released and the storage time when the gate voltage of the 64th electrode is 15V during the storage phase in the SIMION simulation.
[0033] Figure 7 shows the relationship between the number of released ions and the electric field strength in the storage region during the release phase in the SIMION simulation.
[0034] Figure 8 shows the migration spectra of acetone-assisted photoionization of triethyl phosphate with a release time of 30 μs and a storage time ranging from 0 to 400 μs.
[0035] Figure 9 shows the migration spectra of acetone-assisted photoionization of triethyl phosphate with a release time of 50 μs and a storage time ranging from 0 to 400 μs. Detailed Implementation
[0036] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.
[0037] A method for controlling an ion funnel trap. The ion funnel trap is composed of 96 alternately stacked annular metal electrodes with different inner diameters and ceramic pads. The electrode thickness is 0.5 mm and the electrode spacing is 0.5 mm. The ion funnel trap is divided into three regions: the ion introduction region is formed between the first to the sixty-third annular electrodes, with the inner diameter gradually decreasing from 24 mm to 3 mm and then increasing again to 20 mm; the ion storage region is formed between the sixty-fourth and seventy-fifth annular electrodes, with an inner diameter of 20 mm; and the ion extraction region is formed between the seventy-sixth to the ninety-sixth annular electrodes, with the inner diameter gradually decreasing from 20 mm to 3 mm. Ion-permeable metal grids are sequentially arranged inside the sixty-fourth, seventy-fifth, and seventy-sixth electrodes.
[0038] Apart from the electrodes located at the grid positions, the remaining annular electrodes are electrically connected to the power supply via a voltage divider resistor chain, forming DC electric fields in the ion introduction, ion storage, and ion extraction regions of the ion funnel trap, respectively, in the same direction as ion migration. The potentials at the positions corresponding to the sixty-fourth, seventy-fifth, and seventy-sixth electrodes are V, respectively. G1 V G2 、 and V G3 V G1 >V G2 >V G3 During 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 G3 The ion clusters in the storage region will accelerate into the ion extraction region under the influence of a higher DC electric field.
[0042] The difference between timing t3 and t0 is the working period T of the ion funnel trap, which is 30–100 ms. The difference between timing t1 and t0 is defined as the injection time. The difference between timing t2 and t1 is defined as the storage time, which is 0–1000 μs. The difference between timing t3 and t2 is defined as the release time, which is 10–100 μs. The difference between timing t3 and t2 is defined as the injection time.
[0043] When the ion funnel trap is in operation, the electric potential applied to the grid and the DC electric field strength formed by the potential difference between the two ends of the corresponding resistor chain in the storage area are periodically cyclically adjusted according to the aforementioned timing sequence.
[0044] The ion funnel trap employing the working mode disclosed in this invention, as shown in Figure 1, is composed of alternating stacks of annular metal electrodes and ceramic pads with different inner diameters, wherein: 1-96 are annular metal electrodes; 97 is the ion introduction region; 98 is the ion storage region; and 99 is the ion extraction region. The electrode thickness is 0.5 mm, and the electrode spacing is 0.5 mm. The ion funnel trap is divided into three regions: the ion introduction region is from the first electrode to the sixty-third electrode; the ion storage region is formed between the sixty-fourth and seventy-fifth electrodes; and the ion extraction region is from the seventy-sixth to the ninety-sixth electrodes. Metal grids are disposed inside the sixty-fourth, seventy-fifth, and seventy-sixth electrodes.
[0045] Figure 2 shows the voltage of each electrode at different stages in the normal operating mode. Throughout the entire operating cycle, the DC electric field strength of the ion introduction region, ion storage region and ion extraction region of the ion funnel trap is maintained at E1, E2 and E3 respectively. The sixty-fourth electrode is subjected to the corresponding position voltage in the injection stage and the same gate voltage in the storage and release stages. The seventy-fifth and seventy-sixth electrodes are subjected to the corresponding gate voltage in the injection and storage stages and the corresponding position voltage in the release stage.
[0046] Figure 3 illustrates the voltages of each electrode at different stages in the operating mode of the present invention, which changes the electric field of the storage region by changing the grid voltage. Throughout the entire operating cycle, the DC electric field strengths of the ion introduction region, ion storage region, and ion extraction region of the ion funnel trap are maintained at E1, E2, and E3, respectively. The sixty-fourth electrode applies the corresponding position voltage during the injection stage, and applies two different gate voltages, one low and one high, during the storage and release stages, respectively. The seventy-fifth and seventy-sixth electrodes apply the corresponding gate voltages during the injection and storage stages, and apply the corresponding position voltages during the release stage.
[0047] Figure 4 illustrates the voltage of each electrode at different stages in the working mode of changing the electric field of the storage region by changing the DC electric field strength of the storage region disclosed in this invention. Throughout the entire working cycle, the DC electric field strength of the ion introduction region and the ion extraction region of the ion funnel trap is maintained at E1 and E3 respectively. The DC electric field strength of the ion storage region is maintained at E2 during the injection and storage stages, and increased to E2' (E2'>E2) during the release stage. The sixty-fourth electrode is subjected to the corresponding position voltage during the injection stage, and the same gate voltage is applied during the storage and release stages. The seventy-fifth and seventy-sixth electrodes are subjected to the corresponding gate voltages during the injection and storage stages, and the corresponding position voltages are applied during the release stage.
[0048] To illustrate the influence of the control method disclosed in this invention on the distribution of ions in the storage region before release, an ion funnel trap model was established in the ion optics simulation software SIMION. Periodically varying voltages were applied to each electrode using Lua code as shown in Figure 3. The basic parameters were: electric field strength of 10 V / cm in the ion introduction region, 2 V / cm in the ion storage region, 20 V / cm in the ion storage region, a release voltage of 50 V for the 64th electrode, and gate voltages of 2.5 V and 5 V for the 75th and 76th electrodes, respectively. Figure 5 shows the ion distribution in the ion funnel trap storage region when the storage voltage of the 64th electrode was 15 V and the storage times were 0, 100, and 200 μs. As the storage time increased, the center of the ion clusters gradually moved closer to the 75th electrode, and the distribution gradually narrowed. With a release time of 50 μs, the number of 1000 ions of different m / z values released was statistically analyzed as a function of storage time (Figure 6). The number of ions released for each m / z value was increased to some extent, with the most significant increase observed for ions with an m / z of 622.
[0049] Due to circuit limitations, experiments were not conducted to periodically change the electric field of the storage region by modulating the potential difference across the resistor chain corresponding to the storage region. However, simulations were performed in SIMION to investigate the effect of increasing the DC electric field of the storage region during the release phase on the ion release efficiency. The storage time was set to 0 μs, the release time to 50 μs, and the electric field strength of the storage region during both the injection and storage phases to 2 V / cm. The relationship between the number of ions released for each m / z and the electric field strength of the storage region during the release phase was obtained (Figure 7). When the electric field strength of the storage region during the release phase increased from 2 V / cm to 10 V / cm, the number of ions released for m / z values of 80 and 322 increased by 159% and 95%, respectively. The simulation results demonstrate that the control method for increasing the DC electric field of the storage region during the release phase proposed in this invention has a theoretical and simulation basis. However, due to limitations in actual circuit conditions, no experiments were conducted.
[0050] Example
[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] Apply voltages as shown in Figure 3, with the following specific parameters: 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 a radio frequency of 0.98 MHz with a peak-to-peak voltage of 200 V. With a working period of 50 ms and a release time of 30 μs, the migration spectrum of acetone-assisted triethyl phosphate photoionization was recorded as a function of storage time from 0 to 400 μs (Figure 8). The results show that as the storage time increases from 0 to 400 μs, the equivalent mobility is 1.52, 1.42, and 1.23 cm⁻¹, respectively. 2 V -1 s -1The peak heights increased from 20 mV, 18 mV, and 112 mV to 124 mV, 136 mV, and 684 mV, respectively, representing increases of 6.2, 7.5, and 6.1 times. With the ion funnel trap working period set to 50 ms and the release time to 50 μs, the migration spectra of acetone-assisted triethyl phosphate photoionization were recorded as a function of storage time from 0 to 400 μs (Figure 9). The results showed that as the storage time increased from 0 to 400 μs, the equivalent migration mobilities increased to 1.52, 1.42, and 1.23 cm⁻¹, respectively. 2 V -1 s -1 The peak heights increased from 40 mV, 32 mV, and 284 mV to 168 mV, 168 mV, and 928 mV, respectively, representing increases of 4.2, 5.2, and 3.3 times. Clearly, the control method disclosed in this invention (Figure 3) can significantly enhance the signal intensity of each mobility ion within a narrow release time (≤50 μs), and the smaller the release time, the higher the enhancement factor.
Claims
1. A method for controlling an ion funnel trap, wherein the ion funnel trap is composed of ninety-six annular metal electrodes with varying inner diameters in an hourglass shape, stacked coaxially and at equal intervals; along an axial direction from left to right, the first electrode (1) to the sixty-third electrode (63) of the ion funnel trap constitute an ion introduction region (97), the sixty-fourth electrode (64) to the seventy-fifth electrode (75) constitute an ion storage region (98), and the seventy-sixth electrode (76) to the ninety-sixth electrode (96) constitute an ion extraction region (99); wherein, The interiors of the sixty-fourth electrode (64), seventy-fifth electrode (75), and seventy-sixth electrode (76) are all equipped with ion-permeable metal grids. Except for the sixty-fourth electrode (64), seventy-fifth electrode (75), and seventy-sixth electrode (76), the first electrode (1) to the ninety-sixth electrode (96) of the ion funnel trap are electrically connected to the power supply through a voltage divider resistor chain. A DC electric field with the same direction of ion migration is formed in the ion introduction region (97), ion storage region (98), and ion extraction region (99) of the ion funnel trap, respectively. During the working cycle of the ion funnel trap, the electric field strengths of the ion introduction region (97) and the ion extraction region (99) remain constant at E1 and E3, respectively. The potentials at the resistive chain positions corresponding to the sixty-fourth electrode (64), the seventy-fifth electrode (75), and the seventy-sixth electrode (76) are V, respectively. G1 V G2 and V G3 , where V G1 >V G2 >V G3 ; During the working cycle of the ion funnel trap, the electric field strength of the ion storage region (98) is increased with time. At the timing t0≤t<t1, since the electric field strength of the ion storage region (98) is low, ions enter the ion storage region (98) from the ion introduction region (97) through the sixty-fourth electrode (64) and are enriched by suspending along the axis of the ion funnel trap. This stage is regarded as the injection enrichment stage. At the timing t1≤t<t2, since the electric field strength of the ion storage region (98) is moderate, the electric field drives the ions to move towards the seventy-fifth electrode (75), and the ion number density in front of the seventy-fifth electrode (75) increases. This stage is regarded as the storage shaping stage. At the timing t2≤t<t3, due to the high electric field strength of the ion storage region (98), the ions accelerate under the action of the high electric field of the ion storage region (98), pass through the seventy-fifth electrode (75) and the seventy-sixth electrode (76) and enter the ion extraction region (99), and are further transported to the migration spectrum or mass spectrum for separation and detection. This stage is regarded as the pulse release stage.
2. The ion funnel trap control method according to claim 1, characterized in that, The periodic change of the electric field in the ion storage region (98) is achieved by modulating the potential of the sixty-fourth electrode (64), specifically as follows: At 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 that at the corresponding positions. G2 and V G3 Higher potentials V2 and V3, V3>V2>V G2 >V G3 ; At timing t1≤t<t2, 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 sixty-fourth electrode (64) 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 electrode (75) and the seventy-sixth electrode (76), respectively; At timing t2≤t<t3, the electric field intensity E2 is formed by the potential difference between the two ends of the resistor chain corresponding to the ion storage region (98), and a higher voltage V is applied to the sixty-fourth electrode (64). 12 V 12 >V 11 The seventy-fifth electrode (75) and the seventy-sixth electrode (76) are respectively applied with corresponding position potentials V. G2 and V G3 .
3. The ion funnel trap control method according to claim 1, characterized in that, The periodic change of the electric field in the ion storage region (98) is achieved by modulating the electric field intensity formed by the potential difference between the two ends of the resistor chain corresponding to the ion storage region (98), specifically as follows: At 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 that at the corresponding positions. G2 and V G3 Higher potentials V2 and V3, V3>V2>V G2 >V G3 ; At timing t1≤t<t2, 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 sixty-fourth electrode (64) 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 electrode (75) and the seventy-sixth electrode (76), respectively; At timing t2≤t<t3, 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', E2'>E2, and the potential V is applied to the sixty-fourth electrode (64). 11 The seventy-fifth electrode (75) and the seventy-sixth electrode (76) are respectively applied with corresponding position potentials V. G2 and V G3 .
4. A method for controlling an ion funnel trap according to any one of claims 1-3, characterized in that, The difference between timing t3 and t0 is the ion gate working period T, which is 30 to 100 ms. The difference between timing t1 and t0 is defined as the injection time. The difference between timing t2 and t1 is defined as the storage time, which is 0 to 1000 μs. The difference between timing t3 and t2 is defined as the release time, which is 10 to 100 μs.
5. The ion funnel trap control method according to claim 1, characterized in that, When the ion funnel trap is in operation, the potential applied by the sixty-fourth electrode (64), the seventy-fifth electrode (75) and the seventy-sixth electrode (76) or the electric field strength formed by the potential difference at both ends of the resistor chain corresponding to the ion storage region (98) is periodically cyclically adjusted according to the time sequence.