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He X, Guo X, Deng F, Zeng P, Wu B, Sun H, Zhao Z, Duan Y. A study of the transient gas flow affected ion transmission in atmospheric pressure interfaces based on large eddy simulation for electrospray ionization mass spectrometry. Talanta 2024; 274:125980. [PMID: 38579418 DOI: 10.1016/j.talanta.2024.125980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 03/05/2024] [Accepted: 03/20/2024] [Indexed: 04/07/2024]
Abstract
Modern atmosphere pressure interface (API) enables high-efficiency coupling between mass analyzers in high vacuum and atmosphere ionization sources such as electrospray ionization (ESI) source. The transient gas flow entering API possesses strong compressibility and turbulent characteristics, which exerts a huge impact on ion transmission. However, the instantaneous nature and vortical morphology of the turbulence in API and its affection in ion transmission were hardly covered in the reported research. Here we conduct a transient turbulent flow-affected ion transmission evaluation for two typical APIs, the ion funnel and the S-lens, based on scale-resolving large eddy simulation and electro-hydrodynamical ion tracing simulation. In our simulation, the transient properties of the gas flow in the two APIs are illustrated and analyzed in-depth. After experimentally validated on a homemade ESI-TOF-MS platform, the results suggest that the ion funnel can achieve a higher droplet desolvation rate by introducing a unique droplet recirculation mechanism. Meanwhile, the less-dispersed gas flow in S-lens is beneficial in actuating ions axially. In conclusion, the application of the scale-resolving turbulence model helps us to understand the complicated fluid-ion interaction mechanism in APIs and is promising in the development of mass spectrometry instruments of higher performance.
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Affiliation(s)
- Xingliang He
- Research Center of Analytical Instrumentation, School of Mechanical Engineering, Sichuan University, China
| | - Xing Guo
- Research Center of Analytical Instrumentation, School of Mechanical Engineering, Sichuan University, China
| | - Fulong Deng
- Research Center of Analytical Instrumentation, School of Mechanical Engineering, Sichuan University, China
| | - Pengyu Zeng
- Research Center of Analytical Instrumentation, School of Mechanical Engineering, Sichuan University, China
| | - Bin Wu
- Research Center of Analytical Instrumentation, School of Mechanical Engineering, Sichuan University, China
| | - Hong'en Sun
- Research Center of Analytical Instrumentation, School of Mechanical Engineering, Sichuan University, China
| | - Zhongjun Zhao
- Research Center of Analytical Instrumentation, School of Mechanical Engineering, Sichuan University, China; Aliben Science & Technology, China.
| | - Yixiang Duan
- Research Center of Analytical Instrumentation, School of Mechanical Engineering, Sichuan University, China; Aliben Science & Technology, China.
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2
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Song J, Zhang D, Dai X, Huang Z, Fang X, Tian D, Jiang Y. Numerical Analysis and Quantification of Transfer Efficiency Coupled with Capillary and Quadrupole Ion Guide in an API-MS System. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024. [PMID: 38828990 DOI: 10.1021/jasms.4c00097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Abstract
Ion trajectory simulation is a significant and useful tool for understanding ion transfer mechanisms within the first vacuum region of the atmospheric pressure ionization mass spectrometer (API-MS). However, the complex dynamic gas field and wide pressure range lead to inaccurate simulation and huge computational costs. In this work, a novel electrohydrodynamic simulation called the statistical diffusion-hard-sphere (SDHS) mixed collision model was developed for characterizing the ion trajectories. For the first time, the influence of the dynamic pressure on the ion trajectory is considered for simulation, which helps to avoid an intolerable computational cost. Comparing with the conventional Monte Carlo collision model, the SDHS method helps to improve the calculation accuracy of ion trajectories under the first vacuum region and reduce the computational cost for at least 12-folds. Simulation results showed that the maximum ion loss came from the gap of the electrodes. The distance of the capillary-quadrupole ion guide was also a non-negligible factor. The trend of quantitative experimental results matches the SDHS simulation results. The maximum ion transfer efficiencies of quantitative experiment and simulation were 55% and 52%, respectively. Moreover, three ions, caffeine, reserpine, and Ultramark 1621, were measured for evaluating the applicability of SDHS in real API-MS. The trend of experimental results showed good agreement with that of computation. And the results of caffeine further illustrated the reason that the small mass ion transfer efficiency decreased with increasing radio frequency voltage. SDHS method is expected to be useful in the design of ion guides for further improvement of the sensitivity of API-MS.
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Affiliation(s)
- Jiafeng Song
- College of Instrumentation & Electrical Engineering, Jilin University, Changchun 130012, China
| | - Di Zhang
- Technology Innovation Center of Mass Spectrometry for Stata Market Regulation, Center for Advanced Measurement Science, National Institute of Metrology, Beijing 100029, People's Republic of China
| | - Xinhua Dai
- Technology Innovation Center of Mass Spectrometry for Stata Market Regulation, Center for Advanced Measurement Science, National Institute of Metrology, Beijing 100029, People's Republic of China
| | - Zejian Huang
- Technology Innovation Center of Mass Spectrometry for Stata Market Regulation, Center for Advanced Measurement Science, National Institute of Metrology, Beijing 100029, People's Republic of China
| | - Xiang Fang
- Technology Innovation Center of Mass Spectrometry for Stata Market Regulation, Center for Advanced Measurement Science, National Institute of Metrology, Beijing 100029, People's Republic of China
| | - Di Tian
- College of Instrumentation & Electrical Engineering, Jilin University, Changchun 130012, China
| | - You Jiang
- Technology Innovation Center of Mass Spectrometry for Stata Market Regulation, Center for Advanced Measurement Science, National Institute of Metrology, Beijing 100029, People's Republic of China
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3
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Zhou X, Wang Z, Li S, Rong X, Bu J, Liu Q, Ouyang Z. Differentiating enantiomers by directional rotation of ions in a mass spectrometer. Science 2024; 383:612-618. [PMID: 38330101 DOI: 10.1126/science.adj8342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 01/03/2024] [Indexed: 02/10/2024]
Abstract
Conventional mass spectrometry does not distinguish between enantiomers, or mirror-image isomers. Here we report a technique to break the chiral symmetry and to differentiate enantiomers by inducing directional rotation of chiral gas-phase ions. Dual alternating current excitations were applied to manipulate the motions of trapped ions, including the rotation around the center of mass and macro movement around the center of the trap. Differences in collision cross section were induced, which could be measured by ion cloud profiling at high resolutions above 10,000. High-field ion mobility and tandem mass spectrometry analyses of the enantiomers were combined and implemented by using a miniature ion trap mass spectrometer. The effectiveness of the developed method was demonstrated with a variety of organic compounds including amino acids, sugars, and several drug molecules, as well as a proof-of-principle ligand optimization study for asymmetric hydrogenation.
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Affiliation(s)
- Xiaoyu Zhou
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
| | - Zhuofan Wang
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
| | - Shuai Li
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
| | - Xianle Rong
- Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Jiexun Bu
- PURSPEC Technology (Beijing) Ltd., Beijing 100084, China
| | - Qiang Liu
- Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Zheng Ouyang
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
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4
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Development and application of a miniature mass spectrometer with continuous sub-atmospheric pressure interface and integrated ionization source. Talanta 2023; 253:123994. [PMID: 36228556 DOI: 10.1016/j.talanta.2022.123994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 09/25/2022] [Accepted: 10/03/2022] [Indexed: 11/23/2022]
Abstract
For the miniature mass spectrometer (MS) with a continuous atmospheric pressure interface (CAPI), the gas in the multi-stage chambers directly affects the performance of the instrument. In this study, a sealed ionization chamber is designed to couple with a conventional mini CAPI-MS. In this configuration, the gas environment in the first ionization chamber can be flexibly changed to regulate the gas conditions throughout the entire instrument. By studying the effect of gas pressure on the performance of the instrument, we found that the instrument shows some unique advantages when the first ionization chamber is under sub-atmospheric pressure (SAP) conditions, such as reducing the load of the vacuum pump by 40%, achieving pump-free injection for gas and liquid samples, and improving the resolution by a factor of 2 without loss of detection sensitivity. Therefore, we propose a new integrated interface called continuous sub-atmospheric pressure interface (CSAPI) for building a miniature ion trap mass spectrometer. The CSAPI specially integrates sample introduction, gas/ions interface, and ionizations, including electrospray ionization (ESI) and secondary electrospray ionization (SESI), making this system more convenient for non-professional handlers to rapidly identify or monitor target analytes in gaseous- and solution-phase samples. We also use this system to study gas composition to further improve performance, being able to achieve a 5-fold sensitivity and 2-fold resolution improvement. At last, some custom applications of the current CSAPI-MS platform are explored and demonstrated, including real-time monitoring of chemical reactions in solution and long-distance sampling and analysis of dried Chinese herbs. In conclusion, this study provides a new approach to constructing a complete, versatile and practical miniature MS instrument.
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Li C, Chu S, Tan S, Yin X, Jiang Y, Dai X, Gong X, Fang X, Tian D. Towards Higher Sensitivity of Mass Spectrometry: A Perspective From the Mass Analyzers. Front Chem 2021; 9:813359. [PMID: 34993180 PMCID: PMC8724130 DOI: 10.3389/fchem.2021.813359] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 12/06/2021] [Indexed: 01/12/2023] Open
Abstract
Mass spectrometry (MS) is one of the most widely used analytical techniques in many fields. Recent developments in chemical and biological researches have drawn much attention to the measurement of substances with low abundances in samples. Continuous efforts have been made consequently to further improve the sensitivity of MS. Modifications on the mass analyzers of mass spectrometers offer a direct, universal and practical way to obtain higher sensitivity. This review provides a comprehensive overview of the latest developments in mass analyzers for the improvement of mass spectrometers' sensitivity, including quadrupole, ion trap, time-of-flight (TOF) and Fourier transform ion cyclotron (FT-ICR), as well as different combinations of these mass analyzers. The advantages and limitations of different mass analyzers and their combinations are compared and discussed. This review provides guidance to the selection of suitable mass spectrometers in chemical and biological analytical applications. It is also beneficial to the development of novel mass spectrometers.
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Affiliation(s)
- Chang Li
- College of Instrumentation & Electrical Engineering, Jilin University, Changchun, China
| | - Shiying Chu
- Technology Innovation Center of Mass Spectrometry for State Market Regulation, Center for Advanced Measurement Science, National Institute of Metrology, Beijing, People’s Republic ofChina
| | - Siyuan Tan
- Technology Innovation Center of Mass Spectrometry for State Market Regulation, Center for Advanced Measurement Science, National Institute of Metrology, Beijing, People’s Republic ofChina
| | - Xinchi Yin
- Technology Innovation Center of Mass Spectrometry for State Market Regulation, Center for Advanced Measurement Science, National Institute of Metrology, Beijing, People’s Republic ofChina
| | - You Jiang
- Technology Innovation Center of Mass Spectrometry for State Market Regulation, Center for Advanced Measurement Science, National Institute of Metrology, Beijing, People’s Republic ofChina
| | - Xinhua Dai
- Technology Innovation Center of Mass Spectrometry for State Market Regulation, Center for Advanced Measurement Science, National Institute of Metrology, Beijing, People’s Republic ofChina
| | - Xiaoyun Gong
- Technology Innovation Center of Mass Spectrometry for State Market Regulation, Center for Advanced Measurement Science, National Institute of Metrology, Beijing, People’s Republic ofChina
| | - Xiang Fang
- Technology Innovation Center of Mass Spectrometry for State Market Regulation, Center for Advanced Measurement Science, National Institute of Metrology, Beijing, People’s Republic ofChina
| | - Di Tian
- College of Instrumentation & Electrical Engineering, Jilin University, Changchun, China
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6
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Abstract
The ion trap is a unique type of device that is used for quantum studies in physics and mass analysis in chemistry. The space charge effect, which is due to trapping of an excessive number of ions, has long been recognized to be harmful for ion manipulation or mass spectrometry analysis. Here, we show an interesting phenomenon in which the energy exchange through collective interaction between the ion species could be effectively used for ion manipulation and high-quality mass measurement. This observation not only reveals a fundamentally interesting process in ion trap operation but also suggests a new alternative means for mass analysis.
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Affiliation(s)
- Xiaoyu Zhou
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
| | - Zheng Ouyang
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
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Lee JY, Kottke PA, Fedorov AG. Electrohydrodynamics of Gas-Assisted Electrospray Ionization Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:2073-2085. [PMID: 32869991 DOI: 10.1021/jasms.0c00197] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Gas-flow assistance is commonly used in ESI-MS for improved transport and desolvation, and fundamental understanding of the underlying phenomena is essential for improvement of aerodynamic interfaces that couple ESI sources and MS. For this purpose, an electrohydrodynamic model is developed for simulation of charged droplet dynamics under the combined effects of gas flow and electric fields with consideration of space charge interactions within the charged aerosol plume. The model is implemented in COMSOL by exploiting a formalism for establishing the droplet trajectories as a sequence of successive droplets ejected at a frequency defined by the electrospray current. The model is used to assess the effect of two distinct flow configurations and compared to the baseline care of electrospray without assist gas. The simulated flows are jet flows oriented coaxially with the ESI spray, with and without imposed vorticity (swirling). Droplet trajectory simulations of a bimodal droplet population consisting of large primary droplets and small progeny droplets reveal a unique capability for vortical assist jet flow to selectively transmit smaller droplets into the MS due to inertial separation. ESI-MS analysis of fluorinated phosphazines subjected to the different gas flow conditions supports the model predictions. The electrohydrodynamic model developed in this work provides a versatile tool to analyze and design aerodynamic ESI interfaces with rigorous incorporation of drag, inertia, and space-charge repulsion and can be used as a powerful simulation methodology for optimizing charged droplet transmission and ultimately improved analytical performance of gas-assisted ESI-MS workflows.
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Affiliation(s)
- Jung Y Lee
- G. W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Peter A Kottke
- G. W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Andrei G Fedorov
- G. W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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8
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Chiarinelli J, Bolognesi P, Avaldi L. Ion optics simulation of an ion beam setup coupled to an electrospray ionization source, strengths, and limitations. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:073203. [PMID: 32752820 DOI: 10.1063/5.0006641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 07/02/2020] [Indexed: 06/11/2023]
Abstract
A unified approach to achieve a start-to-end ion optics simulation of an ion beam apparatus coupled to an electrospray ionization source is presented. We demonstrate that simulations enable reliable information on the behavior and operation of the apparatus to be obtained, but due to the collisions with the buffer gas in the initial stages of the setup, the results concerning the kinetic energy of the ion beam must be treated with care.
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Affiliation(s)
- J Chiarinelli
- CNR-ISM, Area della Ricerca Roma 1, Monterotondo Scalo, Roma 00015, Italy
| | - P Bolognesi
- CNR-ISM, Area della Ricerca Roma 1, Monterotondo Scalo, Roma 00015, Italy
| | - L Avaldi
- CNR-ISM, Area della Ricerca Roma 1, Monterotondo Scalo, Roma 00015, Italy
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9
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Wang W, Bajic S, John B, Emerson DR. Numerical Simulation of Flow Field and Ion Transport for Different Ion Source Sampling Interfaces of a Mass Spectrometer. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:840-855. [PMID: 32134651 DOI: 10.1021/jasms.9b00103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Understanding ion transport mechanisms in the flow expansion section of the first vacuum region of a mass spectrometer (MS) with an atmospheric pressure ionization source is essential for optimizing the MS sampling interface design. In this study, numerical simulations of three types of ions in two different MS interface designs have been carried out. In contrast to previously reported numerical studies, nonequilibrium gas dynamics due to rarefied gas effects has been considered in modeling the flow expansion and a realistic space charge effect has been considered in a continuous ion injection mode. Numerical simulations reveal that a flat plate interface has a higher peak buffer gas velocity but a narrower zone of silence compared to the conical interface. Shock wave structures are clearly captured, and the Knudsen number distribution is displayed. Simulation results show that in the axial direction the buffer gas effect is much stronger than the electric force effect in the current configuration. The conical interface leads to both a strong ion acceleration in the zone of silence and a strong ion deceleration downstream. In the radial direction, both the electric force and buffer gas drag force play an important role. The conical interface introduces a relatively stronger ion focusing effect from the radial buffer gas effect and a stronger ion dispersion from the radial electric force than the flat plate interface. The net effect for the current configuration is an increase in ion losses for the conical interface. Nanoelectrospray ionization experiments were carried out to validate the ion transmission efficiency.
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Affiliation(s)
- Wei Wang
- STFC, Daresbury Laboratory, Warrington, Cheshire WA4 4AD, U.K
- Waters Corporation, Altrincham Rd, Wilmslow, Cheshire SK9 4AX, U.K
| | - Steve Bajic
- Waters Corporation, Altrincham Rd, Wilmslow, Cheshire SK9 4AX, U.K
| | - Benzi John
- STFC, Daresbury Laboratory, Warrington, Cheshire WA4 4AD, U.K
| | - David R Emerson
- STFC, Daresbury Laboratory, Warrington, Cheshire WA4 4AD, U.K
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Zhou X, Liu X, Ouyang Z. Statistical Algorithm Enables Rapid Computation of Space Charge Effect and Spectral Correction in a Miniature Ion Trap Mass Spectrometer. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:429-433. [PMID: 31940196 DOI: 10.1021/jasms.9b00115] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Computation of the space charge effect within an ion trap may cost a few days to even years in clusters. Here, we report a statistical algorithm that can compute the space charge effect within a few minutes via a personal computer, without scarifying the accuracy. The key technology developed here was an effective electric field extracted from the statistics of N ions to replace the time-consuming computation of ion-ion Coulombic interactions, therefore reducing the computational burden from ∼N2 to ∼N; then, the burden was further reduced by shrinking the sampling size to Nsim = 500. For a linear ion trap (LIT) with an ion capacity N = 1 × 10 5∼1 × 106, this indicated an improved efficiency of N2/Nsim , i.e., 20 million∼2 billion-fold. Using the algorithm, space charge effects under different trapping conditions were explored, and the acquired knowledge enabled the spectral correction of the mass shift and peak broadening due to the effect in a miniature dual-LIT mass spectrometer.
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Affiliation(s)
- Xiaoyu Zhou
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument , Tsinghua University , Beijing 100084 , China
| | - Xinwei Liu
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument , Tsinghua University , Beijing 100084 , China
| | - Zheng Ouyang
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument , Tsinghua University , Beijing 100084 , China
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11
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Huo X, Zhu X, Tang F, Zhang J, Zhang X, Yu Q, Wang X. Discontinuous Subatmospheric Pressure Interface Reduces the Gas Flow Effects on Miniature CAPI Mass Spectrometer. Anal Chem 2020; 92:3707-3715. [PMID: 31961668 DOI: 10.1021/acs.analchem.9b04824] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In the range of miniature mass spectrometers, the miniature ion trap mass spectrometer with continuous atmospheric pressure interface (CAPI) shows good performance potential and advantages due to its excellent sensitivity and analysis speed. However, in previous cases, placing the ion trap directly near the skimmer aperture means it will suffer high gas shock, which may affect performance. In this study, an improved miniature CAPI ion trap mass spectrometer was developed by gas flow optimization. According to the experimental results, excessive gas flow affects stability and resolution. The impact of the gas flow can be effectively reduced by reducing the inner diameter of the skimmer and adding an additional lens element to move the ion trap away from the skimmer aperture. However, this method will affect the sensitivity of the instrument to some extent, so a discontinuous subatmospheric pressure interface (DSPI) was developed to reduce the gas flow effects and improve the comprehensive performance. When using the DSPI system with a 0.4 mm skimmer and entrance lens, the resolution for roxithromycin was up to 2800 at a scanning speed of 1015 Th/s, which was 3.4-fold higher that without DSPI. The dynamic range of concentration reached 4 orders of magnitude and the detection limit for repaglinide was as low as 1 ng/mL. This study offers a new approach to develop better miniature ion trap mass spectrometers and to extend their practical application.
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Affiliation(s)
- Xinming Huo
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China.,Division of Advanced Manufacturing, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China.,Division of Life Science & Health, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Xuanyu Zhu
- Division of Advanced Manufacturing, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China.,Shenzhen CHIN Instrument Co., Ltd., Shenzhen 518052, China
| | - Fei Tang
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
| | - Jian Zhang
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
| | - Xiaohua Zhang
- Department of Chemistry, Fudan University, Shanghai 200433, China
| | - Quan Yu
- Division of Advanced Manufacturing, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Xiaohao Wang
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China.,Division of Advanced Manufacturing, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
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12
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Li M, Liu X, Zhou X, Ouyang Z. Ion-Neutral Collision Effects on Ion Trapping and Pseudopotential Depth in Ion Trap Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:2750-2755. [PMID: 31659717 DOI: 10.1007/s13361-019-02344-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 09/07/2019] [Accepted: 09/25/2019] [Indexed: 06/10/2023]
Abstract
Ion trapping using radio-frequency (RF) devices has been widely used in mass spectrometry (MS). The pseudopotential well (PW) model enables the use of a pseudopotential depth, D, to evaluate the ion trapping capability of the RF devices in the pure electric field. It remains unclear how gas pressures regulate the ion trapping and D. Here, we calculated the D of a linear ion trap (LIT) from 1 mTorr to 2 Torr, a pressure range critical for the operation of the RF devices, through ion cloud simulations. Compared with the case of pure electric field, ion-neutral collision effects at pressures of 1 to 100 mTorr were beneficial for the ion trapping and revealed an optimal trapping depth, D, at around 10 mTorr. We explained the mechanism and validated the observation via ion trapping experiments performed in a home-made dual LIT mass spectrometer. We also showed that near the stability boundary, the RF heating became comparable with the D, which led to the decrement of ion trapping capability characterized by the available D.
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Affiliation(s)
- Ming Li
- NCS Testing Technology CO., Ltd, Beijing, 100081, China
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China
| | - Xinwei Liu
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China
| | - Xiaoyu Zhou
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China.
| | - Zheng Ouyang
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China.
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13
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14
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Draper BE, Anthony SN, Jarrold MF. The FUNPET-a New Hybrid Ion Funnel-Ion Carpet Atmospheric Pressure Interface for the Simultaneous Transmission of a Broad Mass Range. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:2160-2172. [PMID: 30112619 DOI: 10.1007/s13361-018-2038-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Revised: 07/14/2018] [Accepted: 07/16/2018] [Indexed: 06/08/2023]
Abstract
An atmospheric pressure interface transports ions from ambient pressure to the low-pressure environment of a mass spectrometer. A capillary coupled to an ion funnel is widely used. However, conventional ion funnels do little to negate the large amount of energy picked up by high-mass ions from the gas flow through the capillary. There has been little work done on the effects of gas flow on ion transmission, and the previous studies have all been limited to low-mass, low-charge ions. In this work, we account for the effects of gas flow, diffusion, and electric fields (static and oscillating) on ion trajectories and use simulations to design a new hybrid ion funnel-ion carpet (FUNPET) interface that transmits a broad mass range with a single set of instrument conditions. The design incorporates a virtual jet disruptor where pressure buildup and counter flow dissipate the supersonic jet that results from gas flow into the interface. This, and the small exit aperture that can be used with the FUNPET, reduces the gas flow into the next stage of differential pumping. The virtual jet disruptor thermalizes ions with a broad range of masses (1 kDa to 1 GDa), and once thermalized, they are transmitted into next region of the mass spectrometer with low excess kinetic energy. The FUNPET interface is easy to fabricate from flexible printed circuit board and a support frame made by 3D printing. The performance of the interface was evaluated using charge detection mass spectrometry. Graphical Abstract ᅟ.
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Affiliation(s)
- Benjamin E Draper
- Chemistry Department, Indiana University, Bloomington, IN, 47405, USA
| | - Staci N Anthony
- Chemistry Department, Indiana University, Bloomington, IN, 47405, USA
| | - Martin F Jarrold
- Chemistry Department, Indiana University, Bloomington, IN, 47405, USA.
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15
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Zhou X, Liu X, Chiang S, Cao W, Li M, Ouyang Z. Stimulated Motion Suppression (STMS): a New Approach to Break the Resolution Barrier for Ion Trap Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:1738-1744. [PMID: 29845562 DOI: 10.1007/s13361-018-1995-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 05/07/2018] [Accepted: 05/07/2018] [Indexed: 06/08/2023]
Abstract
Ion trap is an excellent platform to perform tandem mass spectrometry (MS/MS), but has an intrinsic drawback in resolving power. Using ion resonant ejection as an example, the resolution degradation can be largely attributed to the broadening of the resonant frequency band (RFB) between ion motion and driving alternative-current (AC). To solve this problem, stimulated motion suppression (STMS) was developed. The key idea of STMS is the use of two suppression alternative-current (SAC) signals, which both have reversed initial phases to the main AC. The SACs can block the unexpected sideband ion resonances (or ejections), therefore playing a key role in sharpening the RFB. The proof-of-concept has been demonstrated through ion trajectory simulations and validated experimentally. STMS provides a new and versatile means for the improvement of the ion trap resolution, which for a long time has reached the bottleneck through conventional methods, e.g., increasing the radio-frequency (RF) voltage and decreasing the mass scan rate. At the end, it is worth noting that the idea of STMS is very general and principally can be applied in any RF device for the purposes of high-resolution mass analysis and ion isolation. Graphical Abstract ᅟ.
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Affiliation(s)
- Xiaoyu Zhou
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China.
| | - Xinwei Liu
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China
| | - Spencer Chiang
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Wenbo Cao
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China
| | - Ming Li
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China
| | - Zheng Ouyang
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China.
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47907, USA.
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Bernier L, Pinfold H, Pauly M, Rauschenbach S, Reiss J. Gas Flow and Ion Transfer in Heated ESI Capillary Interfaces. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:761-773. [PMID: 29468502 DOI: 10.1007/s13361-018-1895-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 01/10/2018] [Accepted: 01/16/2018] [Indexed: 06/08/2023]
Abstract
Transfer capillaries are the preferred means to transport ions, generated by electrospray ionization, from ambient conditions to vacuum. During the transfer of ions through the narrow, long tubes into vacuum, substantial losses are typical. However, recently it was demonstrated that these losses can be avoided altogether. To understand the experimental observation and provide a general model for the ion transport, here, we investigate the ion transport through capillaries by numerical simulation of interacting ions. The simulation encompasses all relevant factors, such as space charge, diffusion, gas flow, and heating. Special attention is paid to the influence of the gas flow on the transmission and especially the change imposed by heating. The gas flow is modeled by a one-dimensional gas dynamics description. A large number of ions are treated as point particles in this gas flow. This allows to investigate the influence of the capillary heating on the gas flow and by this on the ion transport. The results are compared with experimental findings. Graphical Abstract ᅟ.
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Affiliation(s)
| | | | - Matthias Pauly
- MPI f. Solid State Research, Stuttgart, Germany
- CNRS, Institut Charles Sadron, Université de Strasbourg, Strasbourg, France
| | - Stephan Rauschenbach
- MPI f. Solid State Research, Stuttgart, Germany
- Department of Chemistry, Oxford University, Oxford, UK
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Wang W, Bajic S, John B, Emerson DR. Numerical Simulation of Ion Transport in a Nano-Electrospray Ion Source at Atmospheric Pressure. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:600-612. [PMID: 29318469 DOI: 10.1007/s13361-017-1863-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 11/17/2017] [Accepted: 11/27/2017] [Indexed: 06/07/2023]
Abstract
Understanding ion transport properties from the ion source to the mass spectrometer (MS) is essential for optimizing device performance. Numerical simulation helps in understanding of ion transport properties and, furthermore, facilitates instrument design. In contrast to previously reported numerical studies, ion transport simulations in a continuous injection mode whilst considering realistic space-charge effects have been carried out. The flow field was solved using Reynolds-averaged Navier-Stokes (RANS) equations, and a particle-in-cell (PIC) method was applied to solve a time-dependent electric field with local charge density. A series of ion transport simulations were carried out at different cone gas flow rates, ion source currents, and capillary voltages. A force evaluation analysis reveals that the electric force, the drag force, and the Brownian force are the three dominant forces acting on the ions. Both the experimental and simulation results indicate that cone gas flow rates of ≤250 slph (standard liter per hour) are important for high ion transmission efficiency, as higher cone gas flow rates reduce the ion signal significantly. The simulation results also show that the ion transmission efficiency reduces exponentially with an increased ion source current. Additionally, the ion loss due to space-charge effects has been found to be predominant at a higher ion source current, a lower capillary voltage, and a stronger cone gas counterflow. The interaction of the ion driving force, ion opposing force, and ion dispersion is discussed to illustrate ion transport mechanism in the ion source at atmospheric pressure. Graphical Abstract.
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Affiliation(s)
- Wei Wang
- Scientific Computing Department, Science and Technology Facilities Council, Daresbury Laboratory, Sci-Tech Daresbury, Warrington, Cheshire, WA4 4AD, UK.
- Waters Corporation, Altrincham Rd, Wilmslow, Cheshire, SK9 4AX, UK.
| | - Steve Bajic
- Waters Corporation, Altrincham Rd, Wilmslow, Cheshire, SK9 4AX, UK
| | - Benzi John
- Scientific Computing Department, Science and Technology Facilities Council, Daresbury Laboratory, Sci-Tech Daresbury, Warrington, Cheshire, WA4 4AD, UK
| | - David R Emerson
- Scientific Computing Department, Science and Technology Facilities Council, Daresbury Laboratory, Sci-Tech Daresbury, Warrington, Cheshire, WA4 4AD, UK
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Zhou X, Liu X, Cao W, Wang X, Li M, Qiao H, Ouyang Z. Study of In-Trap Ion Clouds by Ion Trajectory Simulations. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:223-229. [PMID: 29043486 DOI: 10.1007/s13361-017-1814-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Revised: 08/29/2017] [Accepted: 09/07/2017] [Indexed: 06/07/2023]
Abstract
Gaussian distribution has been utilized to describe the global number density distribution of ion cloud in the Paul trap, which is known as the thermal equilibrium theory and widely used in theoretical modeling of ion clouds in the ion traps. Using ion trajectory simulations, however, the ion clouds can now also be treated as a dynamic ion flow field and the location-dependent features could now be characterized. This study was carried out to better understand the in-trap ion cloud properties, such as the local particle velocity and temperature. The local ion number densities were found to be heterogeneously distributed in terms of mean and distribution width; the velocity and temperature of the ion flow varied with pressure depending on the flow type of the neutral molecules; and the "quasi-static" equilibrium status can only be achieved after a certain number of collisions, for which the time period is pressure-dependent. This work provides new insights of the ion clouds that are globally stable but subjected to local rf heating and collisional cooling. Graphical Abstract ᅟ.
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Affiliation(s)
- Xiaoyu Zhou
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China
| | - Xinwei Liu
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China
| | - Wenbo Cao
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China
| | - Xiao Wang
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Ming Li
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China
| | - Haoxue Qiao
- Department of Physics, Wuhan University, Wuhan, 430072, China
| | - Zheng Ouyang
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China.
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47907, USA.
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Zhai Y, Zhang X, Xu H, Zheng Y, Yuan T, Xu W. Mini Mass Spectrometer Integrated with a Miniature Ion Funnel. Anal Chem 2017; 89:4177-4183. [PMID: 28252284 DOI: 10.1021/acs.analchem.7b00195] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Yanbing Zhai
- State Key Laboratory
Explosion Science and Technology, School of Life Science, Beijing Institute of Technology, Beijing 100081, China
| | - Xiaohua Zhang
- Anyeep Instrumentation Company, Suzhou 215129, China
| | - Hualei Xu
- State Key Laboratory
Explosion Science and Technology, School of Life Science, Beijing Institute of Technology, Beijing 100081, China
| | - Yongchang Zheng
- Department of Hepatic Surgery, Peking Union Medical College Hospital, Beijing 100032, China
| | - Tao Yuan
- College of Information Science, Shenzhen University, Shenzhen 518060, China
| | - Wei Xu
- State Key Laboratory
Explosion Science and Technology, School of Life Science, Beijing Institute of Technology, Beijing 100081, China
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Affiliation(s)
- Patricia M Peacock
- First State IR, LLC , 118 Susan Drive, Hockessin, Delaware 19707, United States
| | - Wen-Jing Zhang
- Department of Chemistry, Wayne State University , 5101 Cass Avenue, Detroit, Michigan 48202, United States
| | - Sarah Trimpin
- Department of Chemistry, Wayne State University , 5101 Cass Avenue, Detroit, Michigan 48202, United States
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