通過電噴灑游離質譜法進行的分析通常需要進行多個準備步驟，包括定量校準和質量校準。定量校準可能會受到雜訊的影響，而質量校準則可能會受到質量漂移的影響，特別是在長時間分析過程。本文介紹了兩種實現這些校準的方法，通過交流電場調制電噴灑羽流並解調所得的質譜離子電流。為此，我們在電噴灑源和質譜儀入口之間添加了三個環電極。於其中一個電極片施加正弦波訊號，在質譜上記錄呈現波狀特徵的離子電流。此外，在環電極和質譜儀入口之間添加一個nanoESI發射器以提供校準離子。在第一種變體中，使用快速傅里葉變換(FFT)處理在三重四極桿質譜分析儀的離子電流，所得的FFT幅度與分析物濃度相關，以生成校準圖。在第二種變體中，使用四極桿飛行時間質譜分析儀，在波峰處記錄樣品的m/z 值（通過ESI發射器注入），並使用出現在對應波谷時間間隔內的內部標準的 m/z 值進行質量檢查（通過nanoESI發射器注入）。該裝置已通過模擬軟體進行表徵和優化。總體而言，該方法可以產生數量校準圖，並在長時間分析過程中監測（小幅）m/z 漂移。

Analyses conducted by electrospray ionization (ESI) mass spectrometry (MS) typically entail performing a number of preparatory steps, which include quantity calibration and mass calibration. Quantity calibration can be affected by signal noise while mass calibration can be affected by instrumental drift if analyses are performed over an extended period of time. Here, we present two methods for achieving these calibrations using modulation of electrospray plume by alternating electric fields and demodulating the resulting MS ion currents. For this purpose, we use an ESI source fitted with three ring electrodes between the electrospray emitter and the mass spectrometer’s inlet. One of these electrodes is supplied with a sine electric signal. Optionally, a nanoESI emitter is also placed between the ring electrodes and the mass spectrometer’s orifice to supply calibrant ions. The ion currents—recorded with this setup—present wave-like features. In the first variant—using triple quadrupole mass analyzer—the ion currents are subjected to data treatment by fast Fourier transform (FFT), and the resulting FFT magnitudes are correlated with analyte concentrations to produce a calibration plot. In the second variant—using quadrupole time-of-flight mass analyzer—the mass spectra recorded at the wave maxima are mass-checked using the m/z value of internal standard (injected via nanoESI emitter), which appears predominantly in the time intervals corresponding to wave minima. The setup has been characterized using simulation software and optimized. Overall, the method enables preparation of quantity calibration plots, and monitoring (minor) m/z drifts during prolonged analyses.

中文摘要------i
Abstract------ii
謝誌------iii
Table of Contents------v
List of Tables------vi
List of Figures------vii
List of Acronyms------xiii
Chapter 1: Introduction------1
1.1 Electrospray ionization mass spectrometer------1
1.1.1 Electrospray ionization------2
1.1.2 Mass analyzer------5
1.1.2.1 Quadrupole mass analyzer------7
1.1.2.2 Tandem mass spectrometer------9
1.2 Limitations of electrospray ionization------12
1.2.1 Ionization efficiency and transmission efficiency------12
1.2.2 Matrix interference------13
1.3 Improvement of electrospray ionization------14
1.4 Fast Fourier transforms in analytical chemistry------15
1.5 Goal of this study------18
Chapter 2: Electric Field-Modulated Electrospray Ionization Mass Spectrometry for Quantity Calibration and Mass Tracking------19
2.1 Introduction------19
2.2 Experimental section------21
2.1.1 Chemicals------21
2.2.1 Experimental setup for quantitative analysis by QQQ-MS------21
2.2.2 Experimental setup for qualitative analysis by Q-TOF-MS------24
2.2.3 QQQ-MS data treatment------25
2.2.4 Q-TOF-MS data treatment------26
2.2.5 Calculation of mass and charge of microdroplets for simulations------27
2.3 Results and discussion------28
2.3.1 Numerical simulations of the ESI system with three ring electrodes------28
2.3.2 Application of the developed system in quantitative analysis by QQQ-MS------34
2.3.3 Application of the developed system in qualitative analysis by Q-TOF-MS------40
2.4 Concluding remarks------51
Chapter 3: Conclusions and Future Perspective------52
References------54
Appendix 1------69
Appendix 2------70
Appendix 3------71

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