1
|
Zhang D, Loomer M, Gamez G. Quantitative analysis of biopolymers in lignocellulosic biomass feedstocks via laser-assisted micro-pyrolysis flowing atmospheric-pressure afterglow high-resolution ambient mass spectrometry. Talanta 2024; 268:125333. [PMID: 37931586 DOI: 10.1016/j.talanta.2023.125333] [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: 07/28/2023] [Revised: 10/18/2023] [Accepted: 10/21/2023] [Indexed: 11/08/2023]
Abstract
Herein, a diode laser-assisted micro-pyrolysis (LAMP) technique coupled with FAPA high resolution mass spectrometry (HRMS) is demonstrated for fast chemical characterization of lignocellulosic biomass feedstocks. The solid lignocellulosic biomass can be analyzed directly with minimal sample preparation. The mass spectra of the pyrolysis products are interpreted with the aid of data visualization tools such as Kendrick mass defect (KMD) plots and van Krevelen plots. Furthermore, quantitation of lignin/cellulose/hemicellulose, sugar contents of glucan/xylan/galactan/arabinan and lignin monomeric unit S/G is achieved with good accuracy and precision, through multivariate analysis methods, including partial least squares regression (PLSR) and support vector regression (SVR).
Collapse
Affiliation(s)
- Dong Zhang
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX, 79409-1061, USA
| | - Michael Loomer
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX, 79409-1061, USA
| | - Gerardo Gamez
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX, 79409-1061, USA.
| |
Collapse
|
2
|
Thoben C, Hartner NT, Hitzemann M, Raddatz CR, Eckermann M, Belder D, Zimmermann S. Regarding the Influence of Additives and Additional Plasma-Induced Chemical Ionization on Adduct Formation in ESI/IMS/MS. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:857-868. [PMID: 37052511 PMCID: PMC10161231 DOI: 10.1021/jasms.2c00348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Ion mobility spectrometers (IMS) separate ions based on their ion mobility, which depends mainly on collision cross-section, mass, and charge of the ions. However, the performance is often hampered in electrospray ionization (ESI) by the appearance of multiple ion mobility peaks in the spectrum for the same analyte due to clustering and additional sodium adducts. In this work, we investigate the influence of solvents and buffer additives on the detected ion mobility peaks using ESI. Additionally, we investigate the effects of an additional chemical ionization (CI) induced by plasma ionization on the ions formed by electrospray. For this purpose, we coupled our high-resolution IMS with a resolving power of Rp = 100 to a time-of-flight mass spectrometer. Depending on the analyte and the chosen additives, the ionization process can be influenced during the electrospray process. For the herbicide isoproturon, the addition of 5 mM sodium acetate results in the formation of the sodium adduct [M + Na]+, which is reflected in the ion mobility K0 of 1.22 cm2/(V·s). In contrast, the addition of 5 mM ammonium acetate yields the protonated species [M + H]+ and a correspondingly higher K0 of 1.29 cm2/(V·s). In some cases, as with the herbicide pyrimethanil, the addition of sodium acetate can completely suppress ionizations. By carefully choosing the solvent additive for ESI-IMS or additional CI, the formation of different ion mobility peaks can be observed. This can facilitate the assignment of ions to ion mobility peaks using IMS as a compact, stand-alone instrument, e.g., for on-site analysis.
Collapse
Affiliation(s)
- Christian Thoben
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, Appelstr. 9A, 30167 Hannover, Germany
| | - Nora T Hartner
- Leipzig University, Institute of Analytical Chemistry, Linnéstraße 3, 04103 Leipzig, Germany
| | - Moritz Hitzemann
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, Appelstr. 9A, 30167 Hannover, Germany
| | - Christian-Robert Raddatz
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, Appelstr. 9A, 30167 Hannover, Germany
| | - Manuel Eckermann
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, Appelstr. 9A, 30167 Hannover, Germany
| | - Detlev Belder
- Leipzig University, Institute of Analytical Chemistry, Linnéstraße 3, 04103 Leipzig, Germany
| | - Stefan Zimmermann
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, Appelstr. 9A, 30167 Hannover, Germany
| |
Collapse
|
3
|
Weber M, Wolf JC, Haisch C. Effect of Dopants and Gas-Phase Composition on Ionization Behavior and Efficiency in Dielectric Barrier Discharge Ionization. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:538-549. [PMID: 36827232 DOI: 10.1021/jasms.2c00279] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Cold plasma-based ionization techniques allow for soft ionization of a wide variety of chemical compounds. In this chemical ionization mechanism, the atmosphere plays a crucial role in ionization. Knowing its influence is critical for the optimization of analysis conditions and interpretation of resulting spectra. This study uses soft ionization by chemical reaction in transfer (SICRIT), a variant of dielectric barrier discharge ionization (DBDI), that allows for a controlled atmosphere to investigate atmosphere and dopant effects. The influence of eight makeup gas compositions (dry nitrogen, room air, and nitrogen-enriched with either water, HCl, MeOH, hexane, NH3, and fluorobenzene) on the ionization with SICRIT was investigated. Fifteen compound classes, comprising alkanes, polyaromatic hydrocarbons (PAHs), terpenes, oxygen-containing terpenes, alkylphenols, chlorophenols, nitrophenols, trialkylamines, triazines, phthalates with or without ether groups, aldehydes, ketones, fatty acid methyl esters (FAMEs), and polyoxy-methylene ethers (OMEs) were measured via gas chromatography SICRIT high-resolution mass spectrometry (GC-SICRIT-HRMS). The different atmospheres were compared in terms of generated ions, ion intensities and fragmentation during ionization. Measurements of reactant ions were performed for a better understanding of the underlying mechanisms. All 15 compound classes were mostly softly ionized. For most compound classes and atmospheres, protonation is the dominant ionization mode. The highest number of compounds ionized via protonation was observed in dry nitrogen, followed by room air and humid nitrogen. The study should work as a guideline for the choice of atmosphere for specific compound classes and the interpretation of spectra generated under a specific atmosphere.
Collapse
Affiliation(s)
- Markus Weber
- Chair of Analytical Chemistry and Water Chemistry, Technical University of Munich, 85748 Garching, Germany
- Plasmion GmbH, 86167 Augsburg, Germany
| | | | - Christoph Haisch
- Chair of Analytical Chemistry and Water Chemistry, Technical University of Munich, 85748 Garching, Germany
| |
Collapse
|
4
|
Hitzemann M, Schaefer C, Kirk AT, Nitschke A, Lippmann M, Zimmermann S. Easy to assemble dielectric barrier discharge plasma ionization source based on printed circuit boards. Anal Chim Acta 2023; 1239:340649. [PMID: 36628746 DOI: 10.1016/j.aca.2022.340649] [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: 08/13/2022] [Revised: 11/14/2022] [Accepted: 11/20/2022] [Indexed: 11/29/2022]
Abstract
Here, we present a new and an easy to assemble dielectric barrier discharge plasma ionization source based on printed circuit boards with two parallel isolated electrodes for generating a plasma inside an inert fused silica capillary. For demonstration, this plasma source is coupled to an ion mobility spectrometer. With two different sample gas feeds the analytes can either pass through the plasma or bypass the plasma before entering the reaction region of the ion mobility spectrometer, allowing for different ionization pathways, e.g. electron impact ionization, ionization by excited species, e.g. helium metastables, or chemical ionization via reactant ions generated inside or downstream of the plasma. The plasma source, in particular, the electrode geometry and the capillary diameter were designed with the help of electric field simulations. A rectangular electrode with a height of at least twice the outer diameter of the capillary turned out to be ideal, in both the simulation and the experiment. Furthermore, a simple control electronics has been developed, which can be easily applied to other plasma sources. With the plasma source presented here, detection limits in the mid pptv range have been reached.
Collapse
Affiliation(s)
- Moritz Hitzemann
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Appelstr. 9A, 30167, Hannover, Germany.
| | - Christoph Schaefer
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Appelstr. 9A, 30167, Hannover, Germany
| | - Ansgar T Kirk
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Appelstr. 9A, 30167, Hannover, Germany
| | - Alexander Nitschke
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Appelstr. 9A, 30167, Hannover, Germany
| | - Martin Lippmann
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Appelstr. 9A, 30167, Hannover, Germany
| | - Stefan Zimmermann
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Appelstr. 9A, 30167, Hannover, Germany
| |
Collapse
|
5
|
Yue H, He F, Zhao Z, Duan Y. Plasma-based ambient mass spectrometry: Recent progress and applications. MASS SPECTROMETRY REVIEWS 2023; 42:95-130. [PMID: 34128567 DOI: 10.1002/mas.21712] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 05/28/2020] [Accepted: 06/02/2020] [Indexed: 06/12/2023]
Abstract
Ambient mass spectrometry (AMS) has grown as a group of advanced analytical techniques that allow for the direct sampling and ionization of the analytes in different statuses from their native environment without or with minimum sample pretreatments. As a significant category of AMS, plasma-based AMS has gained a lot of attention due to its features that allow rapid, real-time, high-throughput, in vivo, and in situ analysis in various fields, including bioanalysis, pharmaceuticals, forensics, food safety, and mass spectrometry imaging. Tens of new methods have been developed since the introduction of the first plasma-based AMS technique direct analysis in real-time. This review first provides a comprehensive overview of the established plasma-based AMS techniques from their ion source configurations, mechanisms, and developments. Then, the progress of the representative applications in various scientific fields in the past 4 years (January 2017 to January 2021) has been summarized. Finally, we discuss the current challenges and propose the future directions of plasma-based AMS from our perspective.
Collapse
Affiliation(s)
- Hanlu Yue
- College of Life Sciences, Sichuan University, Chengdu, China
| | - Feiyao He
- College of Life Sciences, Sichuan University, Chengdu, China
| | - Zhongjun Zhao
- School of Chemical Engineering, Sichuan University, Chengdu, China
| | - Yixiang Duan
- College of Life Sciences, Sichuan University, Chengdu, China
- School of Manufacturing Science and Engineering, Sichuan University, Chengdu, China
| |
Collapse
|
6
|
Guo X, Pu J, Dai J, Zhao Z, Duan Y. Elucidation of formation mechanism responsible for charge-transfer reagent ions in microwave induced plasma desorption ionization (MIPDI) source. Talanta 2022; 250:123656. [DOI: 10.1016/j.talanta.2022.123656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 05/30/2022] [Accepted: 06/03/2022] [Indexed: 11/29/2022]
|
7
|
Gao Y, Li Y, Zhan B, He Q, Zhu H, Chen W, Yin Q, Feng H, Pan Y. Ambient electric arc ionization for versatile sample analysis using mass spectrometry. Analyst 2021; 146:5682-5690. [PMID: 34397059 DOI: 10.1039/d1an00872b] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel, convenient ambient electric arc ionization (AEAI) device was developed as a mass spectrometry ion source for versatile sample analysis. AEAI could be considered as a soft ionization technique in which the protonated ion ([M + H]+) is the main ion species with little or no in-source fragmentation for most analytes. Coupled with a high-resolution Orbitrap mass spectrometer, AEAI could be applied to the analysis of a variety of organic compounds having a wide range of polarities, ranging from non-polar species such as polybenzenoid aromatic hydrocarbons (PAHs) to highly polar species such as amino acids. With its versatile capabilities in the mass spectrometric analysis of small molecules, AEAI has the potential to be an alternative to traditional ionization methods such as electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI), and electron impact (EI) ionization. The limitations of AEAI are also discussed.
Collapse
Affiliation(s)
- Yuanji Gao
- Department of Chemistry, Zhejiang University, Hangzhou 310027, Zhejiang, P. R. China. .,College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610068, Sichuan, P.R. China
| | - Yuan Li
- Department of Chemistry, Zhejiang University, Hangzhou 310027, Zhejiang, P. R. China.
| | - Binpeng Zhan
- Department of Chemistry, Zhejiang University, Hangzhou 310027, Zhejiang, P. R. China.
| | - Quan He
- Department of Chemistry, Zhejiang University, Hangzhou 310027, Zhejiang, P. R. China.
| | - Heping Zhu
- Department of Chemistry, Zhejiang University, Hangzhou 310027, Zhejiang, P. R. China.
| | - Weiwei Chen
- Department of Chemistry, Zhejiang University, Hangzhou 310027, Zhejiang, P. R. China.
| | - Qi Yin
- Department of Chemistry, Zhejiang University, Hangzhou 310027, Zhejiang, P. R. China.
| | - Hongru Feng
- Department of Chemistry, Zhejiang University, Hangzhou 310027, Zhejiang, P. R. China.
| | - Yuanjiang Pan
- Department of Chemistry, Zhejiang University, Hangzhou 310027, Zhejiang, P. R. China.
| |
Collapse
|
8
|
Molnar BT, Shelley JT. MODERN PLASMA-BASED DESORPTION/IONIZATION: FROM ATOMS AND MOLECULES TO CHEMICAL SYNTHESIS. MASS SPECTROMETRY REVIEWS 2021; 40:609-627. [PMID: 32770688 DOI: 10.1002/mas.21645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 02/05/2020] [Accepted: 07/07/2020] [Indexed: 06/11/2023]
Abstract
Since the first mass spectrometry (MS) experiments were conducted by Thomson and Aston, plasmas have been used as ionization sources. Historically, plasma ion sources were used for these experiments because they were one of the few known sources of gas-phase ions at the time and they were relatively simple to setup and operate. Since then, developments in plasma ionization have continued to inform and motivate advances in other areas of MS. For example, plasma-desorption MS demonstrated ionization of large peptides and polymers more than 10 years before the first descriptions of electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI). As a result, significant effort was placed on development of ionization approaches, mass analysis, and detection approaches for very large molecules: even before the advent of ESI and MALDI. Since then, new analytical challenges and opportunities in plasma ionization have arisen. In this review, the emerging trends in plasma-based ionization for several areas of MS will be discussed, including molecular ionization, elemental ionization, hybrid elemental and molecular ion sources, and unique chemical transformations. © 2020 John Wiley & Sons Ltd. Mass Spec Rev.
Collapse
Affiliation(s)
- Brian T Molnar
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY, 12180
| | - Jacob T Shelley
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY, 12180
| |
Collapse
|
9
|
Latif M, Zhang D, Gamez G. Flowing atmospheric-pressure afterglow drift tube ion mobility spectrometry. Anal Chim Acta 2021; 1163:338507. [PMID: 34024423 DOI: 10.1016/j.aca.2021.338507] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 03/29/2021] [Accepted: 04/06/2021] [Indexed: 10/21/2022]
Abstract
In this work, the flowing atmospheric-pressure afterglow (FAPA) ambient desorption/ionization source has been coupled with stand-alone Drift Tube Ion Mobility Spectrometry (DTIMS) for the first time. A tip repeller electrode, modified to allow higher bias potential still below the Townsend's breakdown, was implemented at the FAPA/DTIMS interface to overcome the opposing potentials and facilitate ion transmission. The effect of the lab-built DTIMS and FAPA's operating conditions (such as plasma voltage, current, gas flow rate, repeller's potential and positioning, FAPA orientation, etc.) on the signal of selected analytes was studied, for both gas-phase injection and desorption. The FAPA reactant ion peak (RIP) reduced mobility coefficient (K0) corresponds to protonated water clusters (H2O)nH+. The FAPA-DTIMS spectra of several selected compounds showed that their K0 agrees with literature values. Moreover, quantitative characterization of acetaminophen and 2,6-di-tert-butylpyridine (2,6-DTBP) based on desorption or gas-phase injection yield limits of detection (LODs) of 0.03 μg and 18 ppb, respectively.
Collapse
Affiliation(s)
- Mohsen Latif
- Department of Chemistry and Biochemistry, Texas Tech University, TX, 79409-1061, Lubbock, USA
| | - Dong Zhang
- Department of Chemistry and Biochemistry, Texas Tech University, TX, 79409-1061, Lubbock, USA
| | - Gerardo Gamez
- Department of Chemistry and Biochemistry, Texas Tech University, TX, 79409-1061, Lubbock, USA.
| |
Collapse
|
10
|
Aghaei M, Bogaerts A. Flowing Atmospheric Pressure Afterglow for Ambient Ionization: Reaction Pathways Revealed by Modeling. Anal Chem 2021; 93:6620-6628. [PMID: 33877800 DOI: 10.1021/acs.analchem.0c04076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We describe the plasma chemistry in a helium flowing atmospheric pressure afterglow (FAPA) used for analytical spectrometry, by means of a quasi-one-dimensional (1D) plasma chemical kinetics model. We study the effect of typical impurities present in the feed gas, as well as the afterglow in ambient humid air. The model provides the species density profiles in the discharge and afterglow regions and the chemical pathways. We demonstrate that H, N, and O atoms are formed in the discharge region, while the dominant reactive neutral species in the afterglow are O3 and NO. He* and He2* are responsible for Penning ionization of O2, N2, H2O, H2, and N, and especially O and H atoms. Besides, He2+ also contributes to ionization of N2, O2, H2O, and O through charge transfer reactions. From the pool of ions created in the discharge, NO+ and (H2O)3H+ are the dominant ions in the afterglow. Moreover, negatively charged clusters, such as NO3H2O- and NO2H2O-, are formed and their pathway is discussed as well. Our model predictions are in line with earlier observations in the literature about the important reagent ions and provide a comprehensive overview of the underlying pathways. The model explains in detail why helium provides a high analytical sensitivity because of high reagent ion formation by both Penning ionization and charge transfer. Such insights are very valuable for improving the analytical performance of this (and other) ambient desorption/ionization source(s).
Collapse
Affiliation(s)
- Maryam Aghaei
- Research group PLASMANT, Chemistry Department, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium
| | - Annemie Bogaerts
- Research group PLASMANT, Chemistry Department, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium
| |
Collapse
|
11
|
Vogel P, Lazarou C, Gazeli O, Brandt S, Franzke J, Moreno-González D. Study of Controlled Atmosphere Flexible Microtube Plasma Soft Ionization Mass Spectrometry for Detection of Volatile Organic Compounds as Potential Biomarkers in Saliva for Cancer. Anal Chem 2020; 92:9722-9729. [PMID: 32579344 DOI: 10.1021/acs.analchem.0c01063] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A new soft ionization device for mass spectrometry is presented using the flexible microtube plasma under controlled atmospheric conditions. The controlled atmosphere flexible microtube plasma consists of the plasma source itself connected to a gas chromatograph and a mass spectrometer using a borosilicate glass cross piece. Controlled atmosphere, for example, nitrogen and/or an oxygen mixture, is introduced to the system to create a clean ionization environment. Reproducibility issues are discussed, and solutions are presented manipulating the gas flow in the cross piece. A proof of concept is shown using a ketone mixture introduced to the mass spectrometer to optimize atmospheric conditions. Furthermore, application of the presented device for the sensitive and nonfragmenting ionization of volatile organic biomarkers relevant for cancer is carried out. Sample treatment for human saliva is described, and relevant candidate biomarkers are measured in the saliva matrix, showing a very good ionization efficiency and neglectable matrix effects with limits of detection below 80 ppt.
Collapse
Affiliation(s)
- Pascal Vogel
- ISAS-Leibniz-Institut für Analytische Wissenschaften, Bunsen Kirchhoff Strasse 11, Dortmund 44139, Germany
| | - Constantinos Lazarou
- FOSS Research Centre for Sustainable Energy, PV Technology, University of Cyprus, 75 Kallipoleos Street, Nicosia 1678, Cyprus
| | - Odhisea Gazeli
- FOSS Research Centre for Sustainable Energy, PV Technology, University of Cyprus, 75 Kallipoleos Street, Nicosia 1678, Cyprus
| | - Sebastian Brandt
- ISAS-Leibniz-Institut für Analytische Wissenschaften, Bunsen Kirchhoff Strasse 11, Dortmund 44139, Germany
| | - Joachim Franzke
- ISAS-Leibniz-Institut für Analytische Wissenschaften, Bunsen Kirchhoff Strasse 11, Dortmund 44139, Germany
| | - David Moreno-González
- ISAS-Leibniz-Institut für Analytische Wissenschaften, Bunsen Kirchhoff Strasse 11, Dortmund 44139, Germany
| |
Collapse
|
12
|
Modeling plasmas in analytical chemistry-an example of cross-fertilization. Anal Bioanal Chem 2020; 412:6059-6083. [PMID: 32236655 DOI: 10.1007/s00216-020-02587-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 02/24/2020] [Accepted: 03/09/2020] [Indexed: 10/24/2022]
Abstract
This paper gives an overview of the modeling work developed in our group in the last 25 years for various plasmas used in analytical spectrochemistry, i.e., glow discharges (GDs), inductively coupled plasmas (ICPs), and laser ablation (LA) for sample introduction in the ICP and for laser-induced breakdown spectroscopy (LIBS). The modeling approaches are briefly presented, which are different for each case, and some characteristic results are illustrated. These plasmas are used not only in analytical chemistry but also in other applications, and the insights obtained in these other fields were quite helpful for us to develop models for the analytical plasmas. Likewise, there is now a huge interest in plasma-liquid interaction, atmospheric pressure glow discharges (APGDs), and dielectric barrier discharges (DBDs) for environmental, medical, and materials applications of plasmas. The insights obtained in these fields are also very relevant for ambient desorption/ionization sources and for liquid sampling, which are nowadays very popular in analytical chemistry, and they could be very helpful in developing models for these sources as well. Graphical abstract.
Collapse
|
13
|
Pu J, Dai J, He F, Zhu S, Zhao Z, Duan Y. Interpretation of Ionization Mechanism Responsible for Reagent Ion and Analyte Formation in Microwave-Induced Plasma Desorption Ionization Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:752-762. [PMID: 32003981 DOI: 10.1021/jasms.0c00027] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Ambient desorption/ionization (ADI) sources coupled to mass spectrometer have gained increasing interest in the field of analytical chemistry for its fast and direct analysis of samples. Among many ADI sources, plasma-based ADI sources are an important branch. Despite its extensive use in mass spectrometry analysis, the ionization mechanism of these sources still remain uncertain. The study on ionization mechanism is of great significance to optimize the design of ion sources and to improve ionization efficiency. In this study, targeted research on a better understanding of afterglow distance effects on ionization process was conducted. Based on the quantified signal expression of reagent ions in mass spectrum, the concept that optimal atmospheric analysis distance of plasma ADI source is defined for the first time. From the perspective of mutual restriction effect between atmospheric components, the formation progress of reagent ions was visually revealed in detail, which involved the initial step of forming precursor reagent ions, the clusters reaction for increasing production of reagent ions, and the matrix effect results in reagent ion depletion. The formation mechanism of reagent ions further clarified the explicit reason for abundant reagent ions generated at an optimal distance. Most importantly, the analyte analysis results verified the significant impact of appropriate distance on ionization efficiency in afterglow region. It was confirmed that the quantity and type of reagent ions intimately influenced the status of analyte ions in mass spectrum.
Collapse
Affiliation(s)
| | - Jianxiong Dai
- College of Chemistry and Material Science, Northwest University, Xi'an 710069, P.R. China
| | | | | | | | | |
Collapse
|
14
|
Zhao Z, Pu J, Dai J, He F, Ren B, Zhang C, Duan Y. A mechanism study of positive ionization processes in flowing atmospheric-pressure afterglow (FAPA) ambient ion source with controlled plasma and ambient conditions. Talanta 2019; 205:120090. [PMID: 31450470 DOI: 10.1016/j.talanta.2019.06.090] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 06/21/2019] [Accepted: 06/26/2019] [Indexed: 01/10/2023]
Abstract
Although plasma based ambient desorption/ionization (ADI) sources have been widely used for direct analysis of complex samples, mass spectrometric imaging, high throughput screening etc., the ionization mechanism of plasma-based ADI remains a mystery by now. In this report, a targeted study was conducted aiming at a better understanding of the ionization processes of plasma-based ambient desorption ionization source. As a representative of ambient desorption ionization source, an FAPA source was used and modified as a test platform to control the plasma discharge parameters and ambient ionization environment such as discharge gases, environmental gases and sampling conditions. Based on the ionization results from different ambient ionization conditions, a new mechanism was proposed to reveal the nature of regent ion production of FAPA. At the same time, the effect of buffer gas was investigated. For the first time, the multi-clustered hydronium ions formed by the massive water vapor in the air were explored to clarify reasons for the occurrence of selective ionization and the factors affecting ionization efficiency in such complex events. In addition, the formation of molecular ions and relevant reagent ions was speculated based on experimental observations.
Collapse
Affiliation(s)
- Zhongjun Zhao
- School of Chemical Engineering, Chengdu, 610064, PR China
| | - Juan Pu
- College of Chemistry, Chengdu, 610064, PR China
| | - Jianxiong Dai
- College of Chemistry and Material Science, Northwest University, Xi'an, 710069, PR China
| | - Feiyao He
- School of Manufacturing Science and Engineering, Sichuan University, Chengdu, 610064, PR China
| | - Biao Ren
- School of Manufacturing Science and Engineering, Sichuan University, Chengdu, 610064, PR China
| | - Chaofan Zhang
- School of Manufacturing Science and Engineering, Sichuan University, Chengdu, 610064, PR China
| | - Yixiang Duan
- School of Manufacturing Science and Engineering, Sichuan University, Chengdu, 610064, PR China.
| |
Collapse
|
15
|
Kuhlmann C, Shelley JT, Engelhard C. Plasma-Based Ambient Desorption/Ionization Mass Spectrometry for the Analysis of Liquid Crystals Employed in Display Devices. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:2101-2113. [PMID: 31385257 DOI: 10.1007/s13361-019-02280-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 06/27/2019] [Accepted: 06/28/2019] [Indexed: 06/10/2023]
Abstract
Liquid-crystal displays (LCDs) are the most frequently used display technology worldwide these days. Due to the rather complex manufacturing process and purity requirements for the chemicals used, quality control and display failure analysis are important analytical tasks. Currently, the state-of-the-art techniques (e.g., high-performance liquid chromatography (HPLC), gas chromatography (GC) coupled to mass spectrometry (MS), time-of-flight secondary ion mass spectrometry (TOF-SIMS), or high-resolution microscopy) are costly and time-consuming. Hence, a new pathway to precisely analyze liquid-crystalline materials and LCDs in their native state is reported. A new approach for direct analysis via plasma-based ambient desorption/ionization mass spectrometry (ADI-MS) offers an inexpensive and faster alternative. In this study, direct analysis in real time (DART), the low-temperature plasma (LTP) probe, and flowing atmospheric-pressure afterglow (FAPA) ADI sources coupled to high-resolution mass spectrometry (HR-MS) are compared based on their capabilities and performance for liquid-crystal analysis. These sources enable direct analyte desorption from a sample surface at ambient conditions and ionize the vaporized analyte molecules in a subsequent step. Primarily, the ionization capabilities of the three ADI sources are compared for individual liquid-crystal standards, mixtures of liquid crystals (LCs), and complex liquid crystal/additive mixtures applied in commercially available LCDs. Furthermore, direct surface analysis from a glass substrate is also performed with ADI-MS to compare their applicability to this type of sample matrix.
Collapse
Affiliation(s)
- Christopher Kuhlmann
- Department of Chemistry and Biology, University of Siegen, Adolf-Reichwein-Str. 2, 57076, Siegen, Germany
| | - Jacob T Shelley
- Department of Chemistry and Biochemistry, Kent State University, 1175 Risman Drive, Kent, OH, 44242, USA
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY, 12180, USA
| | - Carsten Engelhard
- Department of Chemistry and Biology, University of Siegen, Adolf-Reichwein-Str. 2, 57076, Siegen, Germany.
- Center for Micro- and Nanochemistry and Engineering, University of Siegen, Adolf-Reichwein-Str. 2, 57076, Siegen, Germany.
| |
Collapse
|
16
|
You Y, Badal SP, Shelley JT. Automatic Analyte-Ion Recognition and Background Removal for Ambient Mass-Spectrometric Data Based on Cross-Correlation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:1720-1732. [PMID: 31161333 DOI: 10.1007/s13361-019-02246-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 04/17/2019] [Accepted: 05/03/2019] [Indexed: 06/09/2023]
Abstract
Ambient mass spectrometry is a powerful approach for rapid, high-throughput, and direct sample analysis. Due to the open-air desorption and ionization processes, random fluctuations of ambient conditions can lead to large variances in mass-spectral signals over time. The mass-spectral data also can be further complicated due to multiple analytes present in the sample, background-ion signals stemming from the desorption/ionization source itself, and other laboratory-specific conditions (e.g., ambient laboratory air, nearby hardware). Thus, background removal and analyte-ion recognition can be quite difficult, particularly in non-targeted analyses. Here, we demonstrate the use of a cross-correlation-based approach to exploit chemical information encoded in the time domain to group/categorize mass-spectral peaks from a single analysis dataset. Ions that originate from ambient (or other) background species were readily flagged and removed from spectra; the result was a decrease in mass-spectral complexity by over 70% due to the removal of these background ions. Meanwhile, analyte ions were differentiated and categorized based on their time-domain profiles. With sufficient mass resolving-power and mass-spectral acquisition rate, isolated mass spectra containing ions from the same species in a sample could be extracted, leading to a reduction in mass-spectral complexity by more than 98% in some cases. The cross-correlation approach was tested with different ionization sources as well as reproducible and irreproducible sample introduction. Software built in-house enabled fully automated data processing, which can be performed within a few seconds. Ultimately, this approach provides an additional dimension of analyte separation in ambient mass-spectrometric analyses with information that is already recorded throughout the analysis.
Collapse
Affiliation(s)
- Yi You
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH, 44242, USA
| | - Sunil P Badal
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH, 44242, USA
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Jacob T Shelley
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH, 44242, USA.
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA.
| |
Collapse
|
17
|
Huba AK, Mirabelli MF, Zenobi R. Understanding and Optimizing the Ionization of Polycyclic Aromatic Hydrocarbons in Dielectric Barrier Discharge Sources. Anal Chem 2019; 91:10694-10701. [DOI: 10.1021/acs.analchem.9b02044] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Anna Katarina Huba
- Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Mario F. Mirabelli
- Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Renato Zenobi
- Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
| |
Collapse
|
18
|
Zhang Y, Zhao W, Wang D, Zhang H, Chai G, Zhang Q, Lu B, Sun S, Zhang J. Direct Analysis of Carbonyl Compounds by Mass Spectrometry with Double-Region Atmospheric Pressure Chemical Ionization. Anal Chem 2019; 91:5715-5721. [PMID: 30951291 DOI: 10.1021/acs.analchem.8b05834] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Direct analysis of highly reactive volatile species such as the aliphatic aldehydes as vital biomarkers remains a great challenge due to difficulties in the sample pretreatment. To address such a challenge, we herein report the development of a novel double-region atmospheric pressure chemical ionization mass spectrometry (DRAPCI-MS) method. The DRAPCI source implements a separated structural design that uses a focus electrode to divide the discharge and ionization region to reduce sample fragmentation in the ionization process. Counterflow introduction (CFI) configuration was adopted in the DRAPCI source to reduce background noise, while ion transmission efficiency was optimized through simulating the voltage of the focus electrode and the ion trajectory of the ion source. The limits of detection (LODs) of four carbonyl compounds cyclohexanone, hexanal, heptanal, and octanal by DRAPCI-MS were between 0.1 and 3 μg·m-3, approximately two to eight times lower than those by atmospheric pressure chemical ionization mass spectrometry. Additionally, the DRAPCI-MS method carried out effective in situ analyses of the volatile components in expired milk and the exhaled breath of smokers, demonstrating the DRAPCI-MS as a practical tool to analyze complex mixtures. The DRAPCI-MS method provides a rapid, sensitive, and high-throughput technique in the real-time analysis of gaseous small-molecule compounds.
Collapse
Affiliation(s)
- Yihan Zhang
- Zhengzhou Tobacco Research Institute , China National Tobacco Corporation , Zhengzhou 450001 , China
| | - Wuduo Zhao
- Center for Advanced Analysis and Computational Science , Zhengzhou University , Zhengzhou 450001 , China
| | - Dingzhong Wang
- Zhengzhou Tobacco Research Institute , China National Tobacco Corporation , Zhengzhou 450001 , China
| | - Hongtu Zhang
- Department of Chemistry and Biochemistry , The Ohio State University , 100 W. 18th Avenue , Columbus , Ohio 43210 , United States
| | - Guobi Chai
- Zhengzhou Tobacco Research Institute , China National Tobacco Corporation , Zhengzhou 450001 , China
| | - Qidong Zhang
- Zhengzhou Tobacco Research Institute , China National Tobacco Corporation , Zhengzhou 450001 , China
| | - Binbin Lu
- Zhengzhou Tobacco Research Institute , China National Tobacco Corporation , Zhengzhou 450001 , China
| | - Shihao Sun
- Zhengzhou Tobacco Research Institute , China National Tobacco Corporation , Zhengzhou 450001 , China
| | - Jianxun Zhang
- Zhengzhou Tobacco Research Institute , China National Tobacco Corporation , Zhengzhou 450001 , China
| |
Collapse
|
19
|
Feider CL, Krieger A, DeHoog RJ, Eberlin LS. Ambient Ionization Mass Spectrometry: Recent Developments and Applications. Anal Chem 2019; 91:4266-4290. [PMID: 30790515 PMCID: PMC7444024 DOI: 10.1021/acs.analchem.9b00807] [Citation(s) in RCA: 262] [Impact Index Per Article: 52.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Clara L. Feider
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Anna Krieger
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Rachel J. DeHoog
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Livia S. Eberlin
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| |
Collapse
|
20
|
Song L, You Y, Evans-Nguyen T. Surface Acoustic Wave Nebulization with Atmospheric-Pressure Chemical Ionization for Enhanced Ion Signal. Anal Chem 2018; 91:912-918. [PMID: 30481449 DOI: 10.1021/acs.analchem.8b03927] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Many ambient desorption/ionization mass spectrometry (ADI-MS) techniques rely critically on thermal desorption. Meanwhile, the analyte classes that are successfully studied by any particular ADI-MS methods are strongly dependent on the type of ionization source. Generally, spray-based ionization sources favor polar analytes, whereas plasma-based sources can be used for more hydrophobic analytes and are more suitable for molecules with small molar masses. In the present work, classic atmospheric-pressure chemical ionization (APCI) is used. To provide improved desorption performance for APCI, a surface acoustic wave nebulization (SAWN) device was implemented to convert liquid analytes into fine airborne particles. Compared to conventional SAWN that is used solely as an ionization source for liquid samples, the coupling of SAWN and APCI significantly improves ion signal by up to 4 orders of magnitude, reaching comparable ion abundances to those of electrospray ionization (ESI). Additionally, this coupling also extends the applicable mass range of an APCI source, conventionally known for the ionization of small molecules <500 Da. Herein, we discuss cursory evidence of this applicability to a variety of analytes including both polar and nonpolar small molecules and novel peptides that mimic biomolecules upward of 1000 Da. Observed species are similar to ESI-derived ions including doubly charged analyte ions despite presumably different charging mechanisms. SAWN-APCI coupling may thus involve more nuanced ionization pathways in comparison to other ADI approaches.
Collapse
Affiliation(s)
- Linxia Song
- University of South Florida , Tampa , Florida 33620 , United States
| | - Yi You
- Federal Institute for Materials Research and Testing (BAM) , 12489 Berlin , Germany
| | | |
Collapse
|
21
|
Jackson S, Swiner DJ, Capone PC, Badu-Tawiah AK. Thread spray mass spectrometry for direct analysis of capsaicinoids in pepper products. Anal Chim Acta 2018; 1023:81-88. [DOI: 10.1016/j.aca.2018.04.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 03/13/2018] [Accepted: 04/15/2018] [Indexed: 01/05/2023]
|
22
|
Ai W, Nie H, Song S, Liu X, Bai Y, Liu H. A Versatile Integrated Ambient Ionization Source Platform. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:1408-1415. [PMID: 29713963 DOI: 10.1007/s13361-018-1949-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 03/14/2018] [Accepted: 03/18/2018] [Indexed: 06/08/2023]
Abstract
The pursuit of high-throughput sample analysis from complex matrix demands development of multiple ionization techniques with complementary specialties. A versatile integrated ambient ionization source (iAmIS) platform is proposed in this work, based on the idea of integrating multiple functions, enhancing the efficiency of current ionization techniques, extending the applications, and decreasing the cost of the instrument. The design of the iAmIS platform combines flowing atmospheric pressure afterglow (FAPA) source/direct analysis in real time (DART), dielectric barrier discharge ionization (DBDI)/low-temperature plasma (LTP), desorption electrospray ionization (DESI), and laser desorption (LD) technique. All individual and combined ionization modes can be easily attained by modulating parameters. In particular, the FAPA/DART&DESI mode can realize the detection of polar and nonpolar compounds at the same time with two different ionization mechanisms: proton transfer and charge transfer. The introduction of LD contributes to the mass spectrometry imaging and the surface-assisted laser desorption (SALDI) under ambient condition. Compared with other individual or multi-mode ion source, the iAmIS platform provides the flexibility of choosing different ionization modes, broadens the scope of the analyte detection, and facilitates the analysis of complex samples. Graphical abstract ᅟ.
Collapse
Affiliation(s)
- Wanpeng Ai
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, People's Republic of China
| | - Honggang Nie
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, People's Republic of China
| | - Shiyao Song
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, People's Republic of China
| | - Xiaoyun Liu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, People's Republic of China
| | - Yu Bai
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, People's Republic of China.
| | - Huwei Liu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, People's Republic of China
| |
Collapse
|
23
|
Shelley JT, Badal SP, Engelhard C, Hayen H. Ambient desorption/ionization mass spectrometry: evolution from rapid qualitative screening to accurate quantification tool. Anal Bioanal Chem 2018; 410:4061-4076. [PMID: 29700557 DOI: 10.1007/s00216-018-1023-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 03/02/2018] [Accepted: 03/13/2018] [Indexed: 11/24/2022]
Abstract
In this article, some recent trends and developments in ambient desorption/ionization mass spectrometry (ADI-MS) are reviewed, with a special focus on quantitative analyses with direct, open-air sampling. Accurate quantification with ADI-MS is still not routinely performed, but this aspect is considered of utmost importance for the advancement of the field. In fact, several research groups are devoted to the development of novel and optimized ADI-MS approaches. Some key trends include novel sample introduction strategies for improved reproducibility, tailored sample preparation protocols for removing the matrix and matrix effects, and multimode ionization sources. In addition, there is significant interest in quantitative mass spectrometry imaging. Graphical abstract Conceptual diagram of the ambient desorption/ionization mass spectrometry approach with different desorption/ionization probes.
Collapse
Affiliation(s)
- Jacob T Shelley
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY, 12180, USA.
| | - Sunil P Badal
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY, 12180, USA
| | - Carsten Engelhard
- Department of Chemistry and Biology, University of Siegen, Adolf-Reichwein-Straße 2, 57076, Siegen, Germany
| | - Heiko Hayen
- Institute of Inorganic and Analytical Chemistry, University of Münster, Corrensstr. 30, 48149, Münster, Germany.
| |
Collapse
|
24
|
Gyr L, Wolf JC, Franzke J, Zenobi R. Mechanistic Understanding Leads to Increased Ionization Efficiency and Selectivity in Dielectric Barrier Discharge Ionization Mass Spectrometry: A Case Study with Perfluorinated Compounds. Anal Chem 2018; 90:2725-2731. [PMID: 29356499 DOI: 10.1021/acs.analchem.7b04711] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Perfluorinated compounds have unique properties and many practical applications, but are difficult to ionize efficiently with soft ionization methods. An active capillary plasma ionization source based on dielectric barrier discharge ionization (DBDI) coupled with mass spectrometry was used to study the ionization pathway of perfluorinated compounds (PFCs), with the aim of both increasing the ionization efficiency and influencing the selectivity for generating product ions in negative ion mode. Cyclic and linear perfluorinated alkanes were found to mainly form [M - F]- and [M - F + O]- ions, respectively; the [M]-• ion was only obtained at low discharge voltage. Additionally, fluorine attachment [M + F]- was observed mostly for perfluorinated alkenes. An isotope labeling experiment with 18O2 showed that the primary source of oxygen in the substitution reaction is molecular oxygen, reacting with the analyte in the form of O-• ions. The abundance of [M - F + O]- ions can thus be enhanced by increasing the plasma voltage to produce a higher O-• ion density. The loss of the fluorine (without substitution by oxygen) was mainly observed at high frequency, a fact which can be exploited for tuning the ionization toward specific product ions. Overall, the mechanistic understanding of the ionization of PFCs allowed to increase the selectivity of the product ions, resulting in increased ionization efficiency.
Collapse
Affiliation(s)
- Luzia Gyr
- Department of Chemistry and Applied Bioscience, ETH Zurich , CH-8093 Zurich, Switzerland
| | - Jan-Christoph Wolf
- Department of Chemistry and Applied Bioscience, ETH Zurich , CH-8093 Zurich, Switzerland
| | - Joachim Franzke
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V. , Bunsen-Kirchhoff-Straße 11, 44139 Dortmund, Germany
| | - Renato Zenobi
- Department of Chemistry and Applied Bioscience, ETH Zurich , CH-8093 Zurich, Switzerland
| |
Collapse
|
25
|
Yin J, Zhao Z, Zhan X, Duan Y. Exploration and performance evaluation of microwave-induced plasma with different discharge gases for ambient desorption/ionization mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2017; 31:919-927. [PMID: 28401996 DOI: 10.1002/rcm.7861] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 03/10/2017] [Accepted: 03/15/2017] [Indexed: 06/07/2023]
Abstract
RATIONALE Microwave-induced plasma (MIP) with different discharge gases of argon or helium provides significant plasma-based ambient desorption/ionization sources, which have potential applicability in direct analysis of complex samples without any sample pre-treatment. In this study, experiments were conducted to better understand microwave-induced plasma desorption/ionization (MIPDI) sources and the corresponding ionization mechanisms. METHODS Emission spectra of microwave-induced argon (MIP-Ar) and helium (MIP-He) plasmas were obtained from the plasma tail flame of a MIP source. Compounds including L-phenylalanine, L-serine, L-valine, urea, 4-acetaminophen, gallic acid and L-ascorbic acid were analyzed using both sources. Polyethylene glycol 400 (PEG400) oligomers were detected by MIP-Ar and MIP-He mass spectrometry at different microwave powers. Mass spectra of higher molecular weight PEGs (including PEG800, PEG1000 and PEG2000) were also acquired using both sources. RESULTS In the emission spectra, N2 , H-I and O-I species were observed by MIP-Ar/He. In addition, SiO2 , Na-I, Si-I and Si-II species were generated by MIP-He. In the mass spectra of compounds, [M+H]+ , [2M+H]+ , [M+O+H]+ , [M+2O-H]+ and fragment ions were observed. In the mass spectra of PEG400 obtained by MIP-Ar/He at different microwave powers, higher molecular weight oligomers could only be observed with higher microwave power. PEGs with molecular weights as high as 1000 Da were also successfully analyzed by MIPDI. CONCLUSIONS According to the different natures of the samples, either MIP-Ar or MIP-He can be chosen as a working ion source for mass spectrometry. The MIPDI source is potentially applicable to the analysis of compounds with high molecular weights, especially polymers with high degree of polymerization (such as PEG2000), which is a challenging issue for the traditional ambient ionization sources. Copyright © 2017 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Jinwei Yin
- Research Center of Analytical Instrumentation, Key Laboratory of Bio-resource and Eco-environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610064, P.R. China
| | - Zhongjun Zhao
- College of Chemical Engineering, Sichuan University, Chengdu, 610064, P.R. China
| | - Xuefang Zhan
- Research Center of Analytical Instrumentation, Key Laboratory of Bio-resource and Eco-environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610064, P.R. China
| | - Yixiang Duan
- Research Center of Analytical Instrumentation, Key Laboratory of Bio-resource and Eco-environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610064, P.R. China
| |
Collapse
|
26
|
Badal SP, Ratcliff TD, You Y, Breneman CM, Shelley JT. Formation of Pyrylium from Aromatic Systems with a Helium:Oxygen Flowing Atmospheric Pressure Afterglow (FAPA) Plasma Source. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2017; 28:1013-1020. [PMID: 28361384 DOI: 10.1007/s13361-017-1625-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 02/06/2017] [Accepted: 02/07/2017] [Indexed: 06/07/2023]
Abstract
The effects of oxygen addition on a helium-based flowing atmospheric pressure afterglow (FAPA) ionization source are explored. Small amounts of oxygen doped into the helium discharge gas resulted in an increase in abundance of protonated water clusters by at least three times. A corresponding increase in protonated analyte signal was also observed for small polar analytes, such as methanol and acetone. Meanwhile, most other reagent ions (e.g., O2+·, NO+, etc.) significantly decrease in abundance with even 0.1% v/v oxygen in the discharge gas. Interestingly, when analytes that contained aromatic constituents were subjected to a He:O2-FAPA, a unique (M + 3)+ ion resulted, while molecular or protonated molecular ions were rarely detected. Exact-mass measurements revealed that these (M + 3)+ ions correspond to (M - CH + O)+, with the most likely structure being pyrylium. Presence of pyrylium-based ions was further confirmed by tandem mass spectrometry of the (M + 3)+ ion compared with that of a commercially available salt. Lastly, rapid and efficient production of pyrylium in the gas phase was used to convert benzene into pyridine. Though this pyrylium-formation reaction has not been shown before, the reaction is rapid and efficient. Potential reactant species, which could lead to pyrylium formation, were determined from reagent-ion mass spectra. Thermodynamic evaluation of reaction pathways was aided by calculation of the formation enthalpy for pyrylium, which was found to be 689.8 kJ/mol. Based on these results, we propose that this reaction is initiated by ionized ozone (O3+·), proceeds similarly to ozonolysis, and results in the neutral loss of the stable CHO2· radical. Graphical Abstract ᅟ.
Collapse
Affiliation(s)
- Sunil P Badal
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH, 44240, USA
| | - Tyree D Ratcliff
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Yi You
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH, 44240, USA
| | - Curt M Breneman
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Jacob T Shelley
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA.
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH, 44240, USA.
| |
Collapse
|
27
|
Cheng SC, Chen SH, Shiea J. Desorption Flame-Induced Atmospheric Pressure Chemical Ionization Mass Spectrometry for Rapid Real-World Sample Analysis. ACTA ACUST UNITED AC 2017; 6:S0065. [PMID: 28573084 DOI: 10.5702/massspectrometry.s0065] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 01/17/2017] [Indexed: 11/23/2022]
Abstract
Flame-induced atmospheric pressure chemical ionization (FAPCI) is a solvent and high voltage-free APCI technique. It uses a flame to produce charged species that reacts with analytes for ionization, and generates intact molecular ions from organic compounds with minimal fragmentation. In this study, desorption FAPCI/MS was developed to rapidly characterize thermally stable organic compounds in liquid, cream, and solid states. Liquid samples were introduced into the ion source through a heated nebulizer, and the analytes formed in the heated nebulizer reacted with charged species in the source. For cream and solid sample analysis, the samples were positioned near the flame of the FAPCI source for thermal desorption and ionization. This approach provided a useful method to directly characterize samples with minimal pretreatment. Standards and real-world samples, such as drug tablets, ointment, and toy were analyzed to demonstrate the capability of desorption FAPCI/MS for rapid organic compound analysis.
Collapse
Affiliation(s)
- Sy-Chyi Cheng
- Department of Chemistry, National Sun Yat-Sen University
| | - Shih-His Chen
- Department of Chemistry, National Sun Yat-Sen University
| | - Jentaie Shiea
- Department of Chemistry, National Sun Yat-Sen University.,Department of Medicinal and Applied Chemistry, Kaohsiung Medical University
| |
Collapse
|
28
|
Atmospheric-pressure solution-cathode glow discharge: A versatile ion source for atomic and molecular mass spectrometry. Anal Chim Acta 2017; 950:119-128. [DOI: 10.1016/j.aca.2016.10.045] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 10/28/2016] [Accepted: 10/31/2016] [Indexed: 01/12/2023]
|
29
|
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
| |
Collapse
|