Implementation and Characterization of a DAPI-Based Rectilinear Ion Trap Mass Spectrometer
DAPI 기반 직선형 이온 트랩 질량분석기의 구현 및 특성평가
- 주제(키워드) Mass Spectrometer , Rectilinear Ion Trap , Discontinuous Atmospheric Pressure Interface , Software
- 발행기관 서강대학교 일반대학원
- 지도교수 오한빈
- 발행년도 2026
- 학위수여년월 2026. 2
- 학위명 석사
- 학과 및 전공 일반대학원 화학과
- 실제URI http://www.dcollection.net/handler/sogang/000000082668
- UCI I804:11029-000000082668
- 본문언어 영어
- 저작권 논문은 저작권에 의해 보호받습니다.
초록(요약문)
To address the limited domestic development of mass spectrometry instrumentation and demonstrate the feasibility of on-site analysis, this study presents the design and characterization of a miniature mass spectrometer utilizing a rectilinear ion trap (RIT). A flat-electrode RIT with literature-derived geometry (𝑥0 = 𝑦0 = 5.0 mm, z0 = 43.2 mm) was rebuilt and optimized for laboratory conditions. To overcome the pumping capacity constraints of a compact system, a discontinuous atmospheric pressure interface (DAPI) was integrated for pulsed ion introduction. Custom analog electronics were employed for RF voltage scanning, while a developed Python/Qt-based software synchronized the DAPI timing and data acquisition. The system's performance was evaluated using standard samples. A highly linear mass calibration curve (R2 = 0.9931) was established in the low mass range (1–200 𝑚/𝑧), and qualitative ion detection was successfully demonstrated for the extended range of 100– 500 𝑚/𝑧. These results validate the prototype as a functional platform for miniature mass spectrometry, providing a technical foundation for domestic instrument development.
more목차
Chapter 1. Introduction and Overview 1
1.1 Background and Motivation 2
1.2 Overview of Quadrupole and Rectilinear Ion Traps 4
1.2.1 Fundamentals of Quadrupole Ion Traps 5
1.2.2 Linear and Rectilinear Ion Trap Geometries 8
1.2.3 Discontinuous Atmospheric Pressure Interface (DAPI) and Rectilinear Ion Trap 10
1.3 Objectives and Scope of This Study 11
1.4 Organization of the Thesis 13
Chapter 2. Design and Construction of a System RIT-Based Miniature Mass Spectrometer 14
2.1 System Overview 15
2.2 Design and Fabrication of the Rectilinear Ion Trap (RIT) Geometry 17
2.2.1 Design Specifications and Geometrical Parameters 18
2.2.2 Electrode Machining and Assembly Structure 20
2.3 DAPI-Like Inlet and Vacuum System 22
2.3.1 DAPI Operating Principle and Component Selection 22
2.3.2 Vacuum Chamber Design and Port Configuration 24
2.4 Sample Introduction and Ionization Interface 26
2.4.1 Configuration and Optimization of Source 27
2.5 Hybrid RF/HV and Control Electronics 29
2.5.1 Integrated Control and RF Drive 31
2.5.2 High Voltage Power Supply and Signal Mapping 32
2.5.3 Signal Detection and Data Acquisition Chain 32
Chapter 3. Control and Data Acquisition Software for the RIT-MS System 33
3.1 Software Design Objectives and Requirements 34
3.2 Software Architecture 36
3.3 Communication Protocol and Data Processing 39
3.3.1 Packet Structure 40
3.3.2 Command System and Data Reception 40
3.3.3 XML-based Configuration and Hardware Mapping 41
3.4 Scan-Function Editor and Timing Control 42
3.5 Real-Time Monitoring and User Interface 44
3.6 Data Storage and Management 47
3.7 Summary 48
Chapter 4. Performance Evaluation and Application Experiments of the RIT-MS 49
4.1 Experimental Setup 50
4.2 Optimization of Scan Sequence and DAPI Timing 53
4.2.1 Optimization of Scan Sequence and DAPI Timing 55
4.2.2 Cooling Time and Spectral Quality 56
4.3 System Characterization 57
4.3.1 Standard Material Spectrum and Quantitative Analysis 57
4.3.2 Mass Calibration and Linearity 59
4.3.3 Mass Resolution and Reproducibility 61
4.4 Application Experiments 62
4.4.1 Broadband Analysis 63
4.4.2 Paper Spray-Based On-Site Analysis Simulation 65
4.5 Summary 66
Chapter 5. Conclusion and Future Perspectives 67
5.1 Conclusion 68
5.2 Limitations and Future Works 68
References 69
Figures and Tables
Page
Figure 1-1. Geometric evolution of quadrupole ion traps: (a) 3D Paul trap, (b) LIT, and
(c) RIT 6
Figure 1-2. Cross-sectional geometry of the rectilinear ion trap (RIT) 8
Figure 2-1. (a) Functional block diagram of the RIT-MS system, showing the RIT
analyzer and ion detector operating inside the vacuum chamber for ion transport and
detection. (b) Photograph of the actual system integrating the vacuum chamber, DAPI
system, and ion source. 15
Figure 2-2. 3D CAD Geometric design of the rectilinear ion trap (RIT): (a) Cross-
sectional view including 𝑥0, 𝑦0 and slit dimensions, (b) Real image of designed RIT .. 18
Figure 2-3 shows the machined electrode parts and the RIT module assembled using the
ceramic holders inside the vacuum chamber 20
Figure 2-4. (a) Configuration of the DAPI inlet consisting of an NResearch 225P012-21
pinch valve and a 1.60 mm silicone tube, (b) Pressure transients in the RIT chamber
following a short opening of the DAPI-like pinch valve for three tubing configurations
(conductive 1.28 mm i.d., conductive 1.60 mm i.d., and non-conductive silicone 1.60 mm
i.d.) 22
Figure 2-5. Detailed design of the custom vacuum chamber. 3D modeling showing the
configuration of major ports 24
Figure 2-6. (a) Image of ionization source and syringe pump. (b) Microscopic image of a
stable Taylor cone formed under optimized voltage (3.5 KV) and flow rate conditions
without auxiliary gas 27
Figure 3-1. Layered architecture of the RIT-MS control software. It shows the flow of
data and commands between the hardware communication, control logic, scan engine,
and UI layers 36
Figure 3-2. Scan Function Method. Users can directly define the time and voltage
parameters for the ion introduction, cooling, analysis, and pump-down stages to optimize
the DAPI sequence in Software. 42
Figure 3-3. (a) Main GUI screen of the RIT-MS control software. (b) Instrument, (c)
connection and real-time monitoring view 45
Figure 4-1. Overall experimental setup of the operating RIT-MS system. It shows the
integration of the syringe pump, vacuum chamber, electronic control unit 51
Figure 4-2. Scan timing and signal control diagram of RIT-MS. (a) Pinch valve
open/close signal, (b) Vacuum chamber pressure change and recovery, (c) Ion source
voltage control, (d) Endcap Front voltage control for ion injection, (e) Actual data graph
showing the voltage application timing of detectors (CD, EM). 53
Figure 4-3. Mass spectrum of caffeine standard solution (with Nicotinamide IS) obtained
under 3.2 kV spray voltage and 0.06 mL/h flow rate conditions 57
Figure 4-4. Mass calibration curve of the RIT-MS system using standard compounds.
Excellent linearity with 𝑅2 = 0.9931 was confirmed 𝑚/𝑧 in the 100 –500 range. 59
Figure 4-5. Full-scan mass spectrum of a standard mixture obtained in 𝑚/𝑧 100–500 63
