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Tian C, Song H, Ahlmann N, Brandt S, Foest D, Niu G, Franzke J, Speicher L. Soft ionization mechanisms in flexible µ-tube plasma-elucidation of He-, Ar-, Kr-, and Xe-FµTP. Anal Bioanal Chem 2024; 416:4907-4918. [PMID: 39004680 PMCID: PMC11480168 DOI: 10.1007/s00216-024-05419-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 05/29/2024] [Accepted: 06/24/2024] [Indexed: 07/16/2024]
Abstract
The soft ionization mechanism of helium-based plasma seems to be understood while it still remains challenging in argon-based plasma, although many studies have used argon plasmas as a soft ionization source with good ionization efficiencies. In this study, helium, argon, krypton, and xenon were fed into the same discharge geometry, a flexible micro-tube plasma (FµTP), to determine the ionization mechanisms. The FµTPs operated with the named noble gases obtained comparable ionization efficiencies by MS measurements. The optical emission results showed that N2+ were the dominant ions within the helium-FµTP and noble gas ions were dominant for the other plasmas. These ions support the development of excitation and eventually stop at the end of the capillary. Therefore, Penning ionization and charge transfer between plasma and ambient air/analytes in the open atmosphere have been proven not to be the primary soft ionization mechanism. Furthermore, it was found that photoionization played a minor role in soft ionization. Using helium as a diagnosis gas in front of the discharge capillary nozzle of the FµTP, where the sample is usually positioned, shows that helium can be ignited by all of these FµTPs. This demonstrates that the excitation of a diagnosis gas as well as the ionization of analytes is independent of the type of the discharge gas. An alternative mechanism that a transient potential created by the ions is responsible for the soft ionization is subsequently proposed.
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Affiliation(s)
- Caiyan Tian
- Leibniz-Institute for Analytical Sciences - ISAS - eV., Bunsen-Kirchhoff-Straße 11, 44139, Dortmund, Germany
| | - Hao Song
- Leibniz-Institute for Analytical Sciences - ISAS - eV., Bunsen-Kirchhoff-Straße 11, 44139, Dortmund, Germany
| | - Norman Ahlmann
- Leibniz-Institute for Analytical Sciences - ISAS - eV., Bunsen-Kirchhoff-Straße 11, 44139, Dortmund, Germany
| | - Sebastian Brandt
- Leibniz-Institute for Analytical Sciences - ISAS - eV., Bunsen-Kirchhoff-Straße 11, 44139, Dortmund, Germany
| | - Daniel Foest
- Leibniz-Institute for Analytical Sciences - ISAS - eV., Bunsen-Kirchhoff-Straße 11, 44139, Dortmund, Germany
| | - Guanghui Niu
- Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1, 8093, Zurich, Switzerland
| | - Joachim Franzke
- Leibniz-Institute for Analytical Sciences - ISAS - eV., Bunsen-Kirchhoff-Straße 11, 44139, Dortmund, Germany.
| | - Luisa Speicher
- Leibniz-Institute for Analytical Sciences - ISAS - eV., Bunsen-Kirchhoff-Straße 11, 44139, Dortmund, Germany.
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2
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Gazeli O, Elia EA, Argirusis N, Lazarou C, Anastassiou C, Franzke J, Garcia-Reyes JF, Georghiou GE, Agapiou A. Low-cost heat assisted ambient ionization source for mass spectrometry in food and pharmaceutical screening. Analyst 2024; 149:4487-4495. [PMID: 39042100 DOI: 10.1039/d4an00901k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/24/2024]
Abstract
Ambient Ionization Mass Spectrometry (AI-MS) techniques have revolutionized analytical chemistry by enabling rapid analysis of samples under atmospheric conditions with minimal to no preparation. In this study, the optimization of a cold atmospheric plasma for the analysis of food and pharmaceutical samples, liquid and solid, using a Heat-Assisted Dielectric Barrier Discharge Ionization (HA-DBDI) source is described. A significant enhancement in analyte signals was observed when a heating element was introduced into the design, potentially allowing for greater sensitivity. Furthermore, the synergy between the inlet temperature of the mass spectrometer and the heating element allows for precise control over the analytical process, leading to improved detection sensitivity and selectivity. Incorporating computational fluid dynamic (CFD) simulations into the study elucidated how heating modifications can influence gas transport properties, thereby facilitating enhanced analyte detection and increased signal intensity. These findings advance the understanding of HA-DBDI technology and provide valuable insights for optimizing AI-MS methodologies for a wide range of applications in food and pharmaceutical analysis.
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Affiliation(s)
- Odhisea Gazeli
- PHAETHON Centre of Excellence for Intelligent, Efficient and Sustainable Energy Solutions, Nicosia 2109, Cyprus
- ENAL Electromagnetics and Novel Applications Lab, Department of Electrical and Computer Engineering, University of Cyprus, Nicosia 2109, Cyprus
- Analytical Chemistry Research Group, Department of Physical and Analytical Chemistry, University of Jaén, 23071 Jaén, Spain
| | - Efstathios A Elia
- Department of Chemistry, University of Cyprus, P.O. Box 20537, Nicosia, 1678, Cyprus.
| | | | - Constantinos Lazarou
- PHAETHON Centre of Excellence for Intelligent, Efficient and Sustainable Energy Solutions, Nicosia 2109, Cyprus
- ENAL Electromagnetics and Novel Applications Lab, Department of Electrical and Computer Engineering, University of Cyprus, Nicosia 2109, Cyprus
| | - Charalambos Anastassiou
- PHAETHON Centre of Excellence for Intelligent, Efficient and Sustainable Energy Solutions, Nicosia 2109, Cyprus
- ENAL Electromagnetics and Novel Applications Lab, Department of Electrical and Computer Engineering, University of Cyprus, Nicosia 2109, Cyprus
| | - Joachim Franzke
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Bunsen-Kirchhoff-Str. 11, 44139 Dortmund, Germany
| | - Juan F Garcia-Reyes
- Analytical Chemistry Research Group, Department of Physical and Analytical Chemistry, University of Jaén, 23071 Jaén, Spain
| | - George E Georghiou
- PHAETHON Centre of Excellence for Intelligent, Efficient and Sustainable Energy Solutions, Nicosia 2109, Cyprus
- ENAL Electromagnetics and Novel Applications Lab, Department of Electrical and Computer Engineering, University of Cyprus, Nicosia 2109, Cyprus
| | - Agapios Agapiou
- Department of Chemistry, University of Cyprus, P.O. Box 20537, Nicosia, 1678, Cyprus.
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3
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García-Martínez J, Caño-Carrillo I, Gilbert-López B, Bouza M, Beneito-Cambra M, Franzke J, Molina-Díaz A, García-Reyes JF. Miniaturized flexible micro-tube plasma ionization source for the effective ionization of non-easily ionizable pesticides in food with liquid chromatography/mass spectrometry. Talanta 2024; 274:126011. [PMID: 38574537 DOI: 10.1016/j.talanta.2024.126011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/24/2024] [Accepted: 03/27/2024] [Indexed: 04/06/2024]
Abstract
In this article, we have studied the potential of flexible microtube plasma (FμTP) as ionization source for the liquid chromatography high-resolution mass spectrometry detection of non-easily ionizable pesticides (viz. nonpolar and non-ionizable by acid/basic moieties). Phthalimide-related compounds such as dicofol, dinocap, o-phenylphenol, captan, captafol, folpet and their metabolites were studied. Dielectric barrier discharge ionization (DBDI) was examined using two electrode configurations, including the miniaturized one based on a single high-voltage (HV) electrode and a virtual ground electrode configuration (FμTP), and also the two-ring electrode DBDI configuration. Different ionization pathways were observed to ionize these challenging, non-easily ionizable nonpolar compounds, involving nucleophilic substitutions and proton abstraction, with subtle differences in the spectra obtained compared with APCI. An average sensitivity increase of 5-fold was attained compared with the standard APCI source. In addition, more tolerance with matrix effects was observed in both DBDI sources. The importance of the data reported is not just limited to the sensitivity enhancement compared to APCI, but, more notably, to the ability to effectively ionize nonpolar, late-eluting (in reverse-phase chromatography) non-ionizable compounds. Besides o-phenylphenol ([M - H]-), all the parent species were efficiently ionized through different mechanisms involving bond cleavages through the effect of plasma reagent species or its combination with thermal degradation and subsequent ionization. This tool can be used to figure out overlooked nonpolar compounds in different environmental samples of societal interest through non-target screening (NTS) strategies.
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Affiliation(s)
- Julio García-Martínez
- University of Jaén, Analytical Chemistry Research Group (FQM-323), Campus Las Lagunillas, Edif. B3, 23071, Jaén, Spain; University Research Institute for Olives Grove and Olive Oil, University of Jaén, Campus Las Lagunillas, 23071, Jaén, Spain
| | - Irene Caño-Carrillo
- University of Jaén, Analytical Chemistry Research Group (FQM-323), Campus Las Lagunillas, Edif. B3, 23071, Jaén, Spain; University Research Institute for Olives Grove and Olive Oil, University of Jaén, Campus Las Lagunillas, 23071, Jaén, Spain
| | - Bienvenida Gilbert-López
- University of Jaén, Analytical Chemistry Research Group (FQM-323), Campus Las Lagunillas, Edif. B3, 23071, Jaén, Spain; University Research Institute for Olives Grove and Olive Oil, University of Jaén, Campus Las Lagunillas, 23071, Jaén, Spain
| | - Marcos Bouza
- University of Jaén, Analytical Chemistry Research Group (FQM-323), Campus Las Lagunillas, Edif. B3, 23071, Jaén, Spain
| | - Miriam Beneito-Cambra
- University of Jaén, Analytical Chemistry Research Group (FQM-323), Campus Las Lagunillas, Edif. B3, 23071, Jaén, Spain
| | - Joachim Franzke
- Leibniz-Institut für Analytische Wissenschaften -ISAS- e.V, Dortmund, Germany
| | - Antonio Molina-Díaz
- University of Jaén, Analytical Chemistry Research Group (FQM-323), Campus Las Lagunillas, Edif. B3, 23071, Jaén, Spain; University Research Institute for Olives Grove and Olive Oil, University of Jaén, Campus Las Lagunillas, 23071, Jaén, Spain
| | - Juan F García-Reyes
- University of Jaén, Analytical Chemistry Research Group (FQM-323), Campus Las Lagunillas, Edif. B3, 23071, Jaén, Spain; University Research Institute for Olives Grove and Olive Oil, University of Jaén, Campus Las Lagunillas, 23071, Jaén, Spain.
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4
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Bouza M, Ahlmann N, García-Reyes JF, Franzke J. Solvent-Assisted Laser Desorption Flexible Microtube Plasma Mass Spectrometry for Direct Analysis of Dried Samples on Paper. Anal Chem 2023; 95:18370-18378. [PMID: 37902451 PMCID: PMC10733904 DOI: 10.1021/acs.analchem.3c03009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 09/11/2023] [Accepted: 10/20/2023] [Indexed: 10/31/2023]
Abstract
The present study investigated the potential for solvent-assisted laser desorption coupled with flexible microtube plasma ionization mass spectrometry (SALD-FμTP-MS) as a rapid analytical technique for direct analysis of surface-deposited samples. Paper was used as the demonstrative substrate, and an infrared hand-held laser was employed for sample desorption, aiming to explore cost-effective sampling and analysis methods. SALD-FμTP-MS offers several advantages, particularly for biofluid analysis, including affordability, the ability to analyze low sample volumes (<10 μL), expanded chemical coverage, sample and substrate stability, and in situ analysis and high throughput potential. The optimization process involved exploring the use of viscous solvents with high boiling points as liquid matrices. This approach aimed to enhance desorption and ionization efficiencies. Ethylene glycol (EG) was identified as a suitable solvent, which not only improved sensitivity but also ensured substrate stability during analysis. Furthermore, the addition of cosolvents such as acetonitrile/water (1:1) and ethyl acetate further enhanced sensitivity and reproducibility for a standard solution containing amphetamine, imazalil, and cholesterol. Optimized conditions for reproducible and sensitive analysis were determined as 1000 ms of laser exposure time using a 1 μL solvent mixture of 60% EG and 40% acetonitrile (ACN)/water (1:1). A mixture of 60% EG and 40% ACN/water (1:1) resulted in signal enhancements and relative standard deviations of 12, 20, and 13% for the evaluated standards, respectively. The applicability of SALD-FμTP-MS was further evaluated by successfully analyzing food, water, and biological samples, highlighting the potential of SALD-FμTP-MS analysis, particularly for thermolabile and polarity diverse compounds.
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Affiliation(s)
- Marcos Bouza
- Analytical
Chemistry Research Group, Department of Physical and Analytical Chemistry, University of Jaén, Campus Las Lagunillas, 23071 Jaén, Spain
| | - Norman Ahlmann
- ISAS—Leibniz
Institut für Analytische Wissenschaften, Bunsen-Kirchhoff-Str. 11, 44139 Dortmund, Germany
| | - Juan F. García-Reyes
- Analytical
Chemistry Research Group, Department of Physical and Analytical Chemistry, University of Jaén, Campus Las Lagunillas, 23071 Jaén, Spain
| | - Joachim Franzke
- ISAS—Leibniz
Institut für Analytische Wissenschaften, Bunsen-Kirchhoff-Str. 11, 44139 Dortmund, Germany
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5
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Zhang J, Wang J, Ouyang F, Zheng Z, Huang X, Zhang H, He D, He S, Wei H, Yu CY. A smartphone-integrated portable platform based on polychromatic ratiometric fluorescent paper sensors for visual quantitative determination of norfloxacin. Anal Chim Acta 2023; 1279:341837. [PMID: 37827652 DOI: 10.1016/j.aca.2023.341837] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 09/18/2023] [Accepted: 09/19/2023] [Indexed: 10/14/2023]
Abstract
The emergence of "superbugs" due to antibiotics overuse poses a significant threat to human health and security. The development of sensitive and effective antibiotics detection is undoubtedly a prerequisite for addressing antibiotics overuse-associated issues. However, current techniques for monitoring antibiotics typically require costly equipment and well-trained professionals. Hence, we developed herein a rapid, instrument-free, and on-site detection method for antibiotic residues such as norfloxacin (NOR) based on a ratiometric sensing platform utilizing "on-off-on" response properties of polychromatic fluorescence for direct visual quantitative NOR analysis. Specifically, this platform integrated iron ions (Fe3+)-chelated blue carbon dots (BCDs) for signal sensing and red carbon dots (RCDs) as an internal reference. The sensor mechanism is selective quenching of BCDs' blue fluorescence by Fe3+ via an inner filter effect with unaffected RCDs' red fluorescence. Further NOR addition led to competitive binding with BCDs due to Fe3+ shedding from the BCDs' surface for a recovered blue fluorescence signal. Notably, the ratiometric fluorescence sensor demonstrated rapid and highly sensitive NOR detection in a concentration range of 1-70 μM with an impressive detection limit of 6.84 nM. The ratiometric fluorescence sensing platform was constructed by integrating smartphone and paper-based strategies, which exhibited exceptional sensitivity, selectivity, and rapid response for portable, instrument-free, visual quantification of NOR in real samples.
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Affiliation(s)
- Jiaheng Zhang
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China
| | - Jun Wang
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China
| | - Feijun Ouyang
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China
| | - Zhi Zheng
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China
| | - Xiaowan Huang
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China
| | - Haitao Zhang
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China
| | - Dongxiu He
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China
| | - Suisui He
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China.
| | - Hua Wei
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China.
| | - Cui-Yun Yu
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China.
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6
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Bouza M, Ahmed E, Rocío-Bautista P, Brandt S, Franzke J, Molina-Díaz A, García-Reyes JF, Donald WA. Ion Heating in Advanced Dielectric Barrier Discharge Ion Sources for Ambient Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:1145-1152. [PMID: 37231669 PMCID: PMC10251516 DOI: 10.1021/jasms.3c00087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 05/10/2023] [Accepted: 05/12/2023] [Indexed: 05/27/2023]
Abstract
Dielectric barrier discharges (DBD) are highly versatile plasma sources for forming ions at atmospheric pressure and near ambient temperatures for the rapid, direct, and sensitive analysis of molecules by mass spectrometry (MS). Ambient ion sources should ideally form intact ions, as in-source fragmentation can limit sensitivity, increase spectral complexity, and hinder interpretation. Here, we report the measurement of ion internal energy distributions for the four primary classes of DBD-based ion sources, specifically DBD ionization (DBDI), low-temperature plasma (LTP), flexible microtube plasma (FμTP), and active capillary plasma ionization (ACaPI), in addition to atmospheric pressure chemical ionization (APCI) using para-substituted benzylammonium thermometer ions. Surprisingly, the average extent of energy deposited by the use of ACaPI (90.6 kJ mol-1) was ∼40 kJ mol-1 lower than the other ion sources (DBDI, LTP, FμTP, and APCI; 130.2 to 134.1 kJ mol-1) in their conventional configurations, and slightly higher than electrospray ionization (80.8 kJ mol-1). The internal energy distributions did not depend strongly on the sample introduction conditions (i.e., the use of different solvents and sample vaporization temperatures) or the DBD plasma conditions (i.e., maximum applied voltage). By positioning the DBDI, LTP, and FμTP plasma jets on axis with the capillary entrance to the mass spectrometer, the extent of internal energy deposition could be reduced by up to 20 kJ mol-1, although at the expense of sensitivity. Overall, the use of an active capillary-based DBD can result in substantially less fragmentation of ions with labile bonds than alternate DBD sources and APCI with comparably high sensitivity.
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Affiliation(s)
- Marcos Bouza
- Analytical
Chemistry Research Group, Department of Physical and Analytical Chemistry, University of Jaén, Campus Las Lagunillas, 23071 Jaén, Spain
| | - Ezaz Ahmed
- School
of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Priscilla Rocío-Bautista
- Analytical
Chemistry Research Group, Department of Physical and Analytical Chemistry, University of Jaén, Campus Las Lagunillas, 23071 Jaén, Spain
| | - Sebastian Brandt
- ISAS—Leibniz
Institut für Analytische Wissenschaften, Bunsen-Kirchhoff-Str. 11, 44139 Dortmund, Germany
| | - Joachim Franzke
- ISAS—Leibniz
Institut für Analytische Wissenschaften, Bunsen-Kirchhoff-Str. 11, 44139 Dortmund, Germany
| | - Antonio Molina-Díaz
- Analytical
Chemistry Research Group, Department of Physical and Analytical Chemistry, University of Jaén, Campus Las Lagunillas, 23071 Jaén, Spain
| | - Juan F. García-Reyes
- Analytical
Chemistry Research Group, Department of Physical and Analytical Chemistry, University of Jaén, Campus Las Lagunillas, 23071 Jaén, Spain
| | - William A. Donald
- School
of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
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7
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Foest D, Knodel A, Ahrends R, Coman C, Franzke J, Brandt S. Flexible Microtube Plasma for the Consecutive-Ionization of Cholesterol in Nano-Electrospray Mass Spectrometry. Anal Chem 2023. [PMID: 37220280 DOI: 10.1021/acs.analchem.2c04052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Electrospray ionization mass spectrometry (ESI-MS) is an established method for the identification of biomarkers. By nano-ESI (nESI), the polar molecular fraction of complex biological samples can be successfully ionized. In contrast, the less-polar free cholesterol, which serves as an important biomarker for several human diseases, is barely accessible by nESI. Although, complex scan functions of modern high-resolution MS devices are able to increase the signal-to-noise ratio, they are limited by the ionization efficiency of the nESI. One possible method to increase the ionization efficiency is the derivatization with acetyl chloride, however interferences with cholesteryl esters must be considered, so chromatographic separation or complex scan functions may be required. A novel approach to increase the yield of cholesterol ions of the nESI could be the application of a second consecutive-ionization process. This publication presents the flexible microtube plasma (FμTP) as a consecutive-ionization source, which allows the determination of cholesterol in nESI-MS analysis. Focusing on the analytical performance, the nESI-FμTP approach increases the cholesterol signal yield in a complex liver extract by a factor of 49. The repeatability and long-term stability could be successfully evaluated. A linear dynamic range of 1.7 orders of magnitude, a minimum detectability of 5.46 mg/L, and a high accuracy (deviation, -8.1%) demonstrates the nESI-FμTP-MS as an excellent approach for a derivatization-free determination of cholesterol.
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Affiliation(s)
- Daniel Foest
- Miniaturisation, Leibniz-Institut für Analytische Wissenschaften─ISAS─e.V., Bunsen-Kirchhoff-Str. 11, 44139 Dortmund, Germany
| | - Alexander Knodel
- Miniaturisation, Leibniz-Institut für Analytische Wissenschaften─ISAS─e.V., Bunsen-Kirchhoff-Str. 11, 44139 Dortmund, Germany
| | - Robert Ahrends
- Department of Analytical Chemistry, University of Vienna, Währingstr. 38, A-1090 Vienna, Austria
| | - Cristina Coman
- Department of Analytical Chemistry, University of Vienna, Währingstr. 38, A-1090 Vienna, Austria
| | - Joachim Franzke
- Miniaturisation, Leibniz-Institut für Analytische Wissenschaften─ISAS─e.V., Bunsen-Kirchhoff-Str. 11, 44139 Dortmund, Germany
| | - Sebastian Brandt
- Miniaturisation, Leibniz-Institut für Analytische Wissenschaften─ISAS─e.V., Bunsen-Kirchhoff-Str. 11, 44139 Dortmund, Germany
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8
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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.
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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
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9
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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.
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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
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10
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Ayala-Cabrera JF, Montero L, Meckelmann SW, Uteschil F, Schmitz OJ. Review on atmospheric pressure ionization sources for gas chromatography-mass spectrometry. Part I: Current ion source developments and improvements in ionization strategies. Anal Chim Acta 2022; 1238:340353. [DOI: 10.1016/j.aca.2022.340353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 08/24/2022] [Accepted: 09/02/2022] [Indexed: 11/26/2022]
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11
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Ayala-Cabrera JF, Montero L, Meckelmann SW, Uteschil F, Schmitz OJ. Review on atmospheric pressure ionization sources for gas chromatography-mass spectrometry. Part II: Current applications. Anal Chim Acta 2022; 1238:340379. [DOI: 10.1016/j.aca.2022.340379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 09/06/2022] [Accepted: 09/07/2022] [Indexed: 11/26/2022]
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12
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Li L, Zhang T, Ge W, He X, Zhang Y, Wang X, Li P. Detection of Trace Explosives Using a Novel Sample Introduction and Ionization Method. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27144551. [PMID: 35889424 PMCID: PMC9320169 DOI: 10.3390/molecules27144551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/06/2022] [Accepted: 07/15/2022] [Indexed: 11/16/2022]
Abstract
A novel sample introduction and ionization method for trace explosives detection is proposed and investigated herein, taking into consideration real-world application requirements. A thermal desorption sampling method and dielectric barrier discharge ionization (DBDI) source, with air as the discharge gas, were developed. The counter flow method was adopted firstly into the DBDI source to remove the interference of ozone and other reactive nitrogen oxides. A separated reaction region with an ion guiding electric field was developed for ionization of the sample molecules. Coupled with a homemade miniature digital linear ion trap mass spectrometer, this compact and robust design, with further optimization, has the advantages of soft ionization, a low detection limit, is free of reagent and consumable gas, and is an easy sample introduction. A range of common nitro-based explosives including TNT, 2,4-DNT, NG, RDX, PETN, and HMX has been studied. A linear response in the range of two orders of magnitude with a limit of detection (LOD) of 0.01 ng for TNT has been demonstrated. Application to the detection of real explosives and simulated mixed samples has also been explored. The work paves the path to developing next generation mass spectrometry (MS) based explosive trace detectors (ETDs).
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Affiliation(s)
- Lingfeng Li
- School of Electronic and Information Engineering, Soochow University, Suzhou 215006, China; (L.L.); (T.Z.); (W.G.); (X.H.); (Y.Z.)
| | - Tianyi Zhang
- School of Electronic and Information Engineering, Soochow University, Suzhou 215006, China; (L.L.); (T.Z.); (W.G.); (X.H.); (Y.Z.)
| | - Wei Ge
- School of Electronic and Information Engineering, Soochow University, Suzhou 215006, China; (L.L.); (T.Z.); (W.G.); (X.H.); (Y.Z.)
| | - Xingli He
- School of Electronic and Information Engineering, Soochow University, Suzhou 215006, China; (L.L.); (T.Z.); (W.G.); (X.H.); (Y.Z.)
| | - Yunjing Zhang
- School of Electronic and Information Engineering, Soochow University, Suzhou 215006, China; (L.L.); (T.Z.); (W.G.); (X.H.); (Y.Z.)
| | - Xiaozhi Wang
- College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027, China;
| | - Peng Li
- School of Electronic and Information Engineering, Soochow University, Suzhou 215006, China; (L.L.); (T.Z.); (W.G.); (X.H.); (Y.Z.)
- Correspondence: ; Tel.: +86-13656249881
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13
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Ayala-Cabrera JF, Turkowski J, Uteschil F, Schmitz OJ. Development of a Tube Plasma Ion Source for Gas Chromatography-Mass Spectrometry Analysis and Comparison with Other Atmospheric Pressure Ionization Techniques. Anal Chem 2022; 94:9595-9602. [PMID: 35758294 DOI: 10.1021/acs.analchem.2c00582] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A tube plasma ionization (TPI) open-air source for gas chromatography-mass spectrometry (GC-MS) was developed. This source is based on an inverse low temperature plasma configuration where the pin inner electrode is applying the high voltage and the grounded electrode is the housing itself. The ionization possibilities were tested by using an EPA mix of priority contaminants, showing that 68% of the analytes could undergo both proton-transfer and charge-exchange reactions. The potential of using different discharge gases (He and Ar) to ionize the analytes and auxiliary gases (He, N2, O2, and synthetic air) to transport the ions toward the MS was carefully investigated. Additionally, the addition of water was also tested to show the different ionization trends in the TPI source. Finally, the ionization by TPI under both dry and wet conditions was compared with other gas-phase atmospheric pressure ionization sources showing TPI could ionize a wider range of compounds (97%) than atmospheric pressure chemical ionization (APCI, 95%) and atmospheric pressure photoionization (APPI, 87%). Besides, the detection capability of TPI was better than APCI and APPI, achieving instrumental limits of detection down to 3 fg on column, which demonstrates the great potential of this ionization source for GC-MS determinations.
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Affiliation(s)
- Juan F Ayala-Cabrera
- Applied Analytical Chemistry, University of Duisburg-Essen, Universitaetsstr. 5, 45141 Essen, Germany.,Teaching and Research Center for Separation, University of Duisburg-Essen, Universitaetsstr. 5, 45141 Essen, Germany
| | - Jasmin Turkowski
- Applied Analytical Chemistry, University of Duisburg-Essen, Universitaetsstr. 5, 45141 Essen, Germany.,Teaching and Research Center for Separation, University of Duisburg-Essen, Universitaetsstr. 5, 45141 Essen, Germany
| | - Florian Uteschil
- Applied Analytical Chemistry, University of Duisburg-Essen, Universitaetsstr. 5, 45141 Essen, Germany.,Teaching and Research Center for Separation, University of Duisburg-Essen, Universitaetsstr. 5, 45141 Essen, Germany
| | - Oliver J Schmitz
- Applied Analytical Chemistry, University of Duisburg-Essen, Universitaetsstr. 5, 45141 Essen, Germany.,Teaching and Research Center for Separation, University of Duisburg-Essen, Universitaetsstr. 5, 45141 Essen, Germany
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14
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Ionization of semi-fluorinated n-alkanes in controlled atmosphere using flexible micro-tube plasma (FμTP) ionization source with square- and sine-wave voltage. Talanta 2022; 249:123662. [PMID: 35691129 DOI: 10.1016/j.talanta.2022.123662] [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: 02/07/2022] [Revised: 05/10/2022] [Accepted: 06/04/2022] [Indexed: 11/21/2022]
Abstract
Non-thermal plasma-based ionization sources have been widely used and shown excellent soft ionization performance in mass spectrometry. Despite their extensive application, the ionization mechanisms of these sources are of great interest for further exploring their full potential. A controlled atmosphere can provide a clean and controllable ionization environment and is beneficial for studying the ionization mechanism. The plasma source itself also has a significant impact on the ionization mechanism of the analyte, and the voltage waveform is one of the key parameters for controlling the plasma source. In this paper, a miniature flexible micro-tube plasma (FμTP) ionization source was sustained using both square and sine-wave voltage. The ionization processes of typical semi-fluorinated n-alkanes (SFAs) were investigated in the controlled atmosphere filled with 80% N2 and 20% O2. The main mass peaks using both square and sine-wave voltages are found to be [M-mH]+ and [M-mH+nO]+ (m = 1, 3; n = 0, 1, 2). However, for the square-wave voltage, the [M-H+O]+ species are the most abundant while [M-H]+ species are dominant for the sine-wave voltage, showing that the plasma generated with sine-wave voltage is somewhat "softer" than the one with square-wave voltage for SFAs. With the assistance of optical spectroscopy, the plasma developments in one discharge cycle for both voltage waveforms were obtained. Only one discharge can be found in each half cycle for square-wave voltage while several for the sine-wave voltage. These would be responsible for the different ionization behaviors in these two cases. This work provides more insight into the ionization mechanism of SFAs and more understanding of plasma-based soft ionization. In addition, the analytical performance was evaluated to be comparable when using these two voltage generators with a big difference in cost, which will benefit the instrumental development.
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15
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Foest D, Knodel A, Brandt S, Franzke J. Coupling paper spray ionization with the flexible microtube plasma for the determination of low polar biomarkers in mass spectrometry. Anal Chim Acta 2022; 1201:339619. [DOI: 10.1016/j.aca.2022.339619] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 01/21/2022] [Accepted: 02/14/2022] [Indexed: 11/15/2022]
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16
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Moreno-González D, Castilla-Fernández D, Vogel P, Niu G, Brandt S, Drees C, García-Reyes JF, Molina-Díaz A, Franzke J. Evaluation of a novel controlled-atmosphere flexible microtube plasma soft ionization source for the determination of BTEX in olive oil by headspace-gas chromatography/mass spectrometry. Anal Chim Acta 2021; 1179:338835. [PMID: 34535252 DOI: 10.1016/j.aca.2021.338835] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 06/28/2021] [Accepted: 07/04/2021] [Indexed: 01/11/2023]
Abstract
Although electron impact ionization (EI) remains the standard ionization source for GC-MS, it presents extensive fragmentation as its main limitation. The potential of a novel plasma-based soft ionization source named controlled-atmosphere flexible microtube plasma (CA-FμTP) has been evaluated in this work for the determination of monoaromatic volatile BTEX group (namely benzene, toluene, ethylbenzene, and o-, m- and p-xylenes) in olive oil, based on headspace technique. The obtained results show an attractive advantage over EI due to no fragmentation was observed. A nitrosated ion [M + NO]+ is obtained as the most abundant species. Thus, the BTEX mass spectrum identification can be carried out without major effort. In general, the sensitivity for CA-FμTP was comparable to those obtained by EI, achieving LODs ranged from 0.6 to 1.0 μg kg-1. The potential usefulness of GC-CA-FμTP-MS for the detection of BTEX was demonstrated by analyzing olive oil samples and identifying traces of these compounds in one sample. Therefore, the proposed plasma-based soft ionization is suitable for BTEX analysis in fatty complex matrixes as olive oil.
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Affiliation(s)
- David Moreno-González
- ISAS-Leibniz-Institut für Analytische Wissenschaften, Dortmund, 44139, Germany; Analytical Chemistry Research Group, Department of Physical and Analytical Chemistry, University of Jaén, 23071, Jaén, Spain.
| | - Delia Castilla-Fernández
- Analytical Chemistry Research Group, Department of Physical and Analytical Chemistry, University of Jaén, 23071, Jaén, Spain
| | - Pascal Vogel
- ISAS-Leibniz-Institut für Analytische Wissenschaften, Dortmund, 44139, Germany
| | - Guanghui Niu
- ISAS-Leibniz-Institut für Analytische Wissenschaften, Dortmund, 44139, Germany
| | - Sebastian Brandt
- ISAS-Leibniz-Institut für Analytische Wissenschaften, Dortmund, 44139, Germany
| | - Carolin Drees
- ISAS-Leibniz-Institut für Analytische Wissenschaften, Dortmund, 44139, Germany
| | - Juan F García-Reyes
- Analytical Chemistry Research Group, Department of Physical and Analytical Chemistry, University of Jaén, 23071, Jaén, Spain
| | - Antonio Molina-Díaz
- Analytical Chemistry Research Group, Department of Physical and Analytical Chemistry, University of Jaén, 23071, Jaén, Spain; Center for Advanced Studies in Olives Grove and Olive Oils (CEAOAO), Science and Technology Park GEOLIT, 23620, Mengíbar, Spain
| | - Joachim Franzke
- ISAS-Leibniz-Institut für Analytische Wissenschaften, Dortmund, 44139, Germany
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Buckley BT, Buckley R, Doherty CL. Moving toward a Handheld "Plasma" Spectrometer for Elemental Analysis, Putting the Power of the Atom (Ion) in the Palm of Your Hand. Molecules 2021; 26:4761. [PMID: 34443348 PMCID: PMC8400342 DOI: 10.3390/molecules26164761] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 07/26/2021] [Accepted: 08/03/2021] [Indexed: 11/16/2022] Open
Abstract
Many of the current innovations in instrument design have been focused on making them smaller, more rugged, and eventually field transportable. The ultimate application is obvious, carrying the instrument to the field for real time sample analysis without the need for a support laboratory. Real time data are priceless when screening either biological or environmental samples, as mitigation strategies can be initiated immediately upon the discovery that contaminant metals are present in a location they were not intended to be. Additionally, smaller "handheld" instruments generally require less sample for analysis, possibly increasing sensitivity, another advantage to instrument miniaturization. While many other instruments can be made smaller just by using available micro-technologies (e.g., eNose), shrinking an ICP-MS or AES to something someone might carry in a backpack or pocket is now closer to reality than in the past, and can be traced to its origins based on a component-by-component evaluation. While the optical and mass spectrometers continue to shrink in size, the ion/excitation source remains a challenge as a tradeoff exists between excitation capabilities and the power requirements for the plasma's generation. Other supporting elements have only recently become small enough for transport. A systematic review of both where the plasma spectrometer started and the evolution of technologies currently available may provide the roadmap necessary to miniaturize the spectrometer. We identify criteria on a component-by-component basis that need to be addressed in designing a miniaturized device and recognize components (e.g., source) that probably require further optimization. For example, the excitation/ionization source must be energetic enough to take a metal from a solid state to its ionic state. Previously, a plasma required a radio frequency generator or high-power DC source, but excitation can now be accomplished with non-thermal (cold) plasma sources. Sample introduction, for solids, liquids, and gasses, presents challenges for all sources in a field instrument. Next, the interface between source and a mass detector usually requires pressure reduction techniques to get an ion from plasma to the spectrometer. Currently, plasma mass spectrometers are field ready but not necessarily handheld. Optical emission spectrometers are already capable of getting photons to the detector but could eventually be connected to your phone. Inert plasma gas generation is close to field ready if nitrogen generators can be miniaturized. Many of these components are already commercially available or at least have been reported in the literature. Comparisons to other "handheld" elemental analysis devices that employ XRF, LIBS, and electrochemical methods (and their limitations) demonstrate that a "cold" plasma-based spectrometer can be more than competitive. Migrating the cold plasma from an emission only source to a mass spectrometer source, would allow both analyte identification and potentially source apportionment through isotopic fingerprinting, and may be the last major hurdle to overcome. Finally, we offer a possible design to aid in making the cold plasma source more applicable to a field deployment.
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Affiliation(s)
- Brian T. Buckley
- Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ 08854, USA;
| | - Rachel Buckley
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA;
| | - Cathleen L. Doherty
- Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ 08854, USA;
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18
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Xu W, Shen Z, Zhang J, Zhang T, Wu H, Wang C, Yu J, Tang K. Hollow electrode capillary plasma ionization source for rapid online detection of gaseous samples. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2021; 35:e9099. [PMID: 33837602 DOI: 10.1002/rcm.9099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 03/05/2021] [Accepted: 04/04/2021] [Indexed: 06/12/2023]
Abstract
RATIONALE Gas chromatography mass spectrometry (GC-MS) with electron ionization (EI) is the most widely used analysis technique of gaseous samples, but it may be time-consuming for online monitoring of mixtures whose concentrations relatively change rapidly. On the contrary, current ionization methods, such as chemical ionization (CI) and proton transfer reaction (PTR), also have some disadvantages such as selectivity. Therefore, appropriate soft ionization sources are searched for rapid online detection. METHODS Hollow electrode capillary plasma ionization (HECPI) is based on single electrode plasma. A hollow capillary was placed as both the electrode and the inlet of the gaseous samples. The ionization source is coupled with a mass spectrometer for performance evaluation. RESULTS Several typical compounds have been tested with HECPI-mass spectrometer. In this process, the dominant ion peaks of all compounds can be indexed as molecular ion peaks, and the product ions of HECPI are less than that of dielectric barrier discharge ionization (DBDI). Three gaseous samples (linalool, triethylamine, and styrene) with various concentrations have been used to further confirm the performance of this source, and the detection limit of linalool is as low as 10 ppb. CONCLUSIONS HECPI is simple in structure and shows good performance. The results also show that HECPI has the potential to be an effective tool for detecting online gaseous samples rapidly.
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Affiliation(s)
- Wen Xu
- Faculty of Electrical Engineering and Computer Science, Ningbo University, Ningbo, China
- Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis of Zhejiang Province, Institute of Mass Spectrometry, Ningbo University, Ningbo, China
| | - Zeyue Shen
- Faculty of Electrical Engineering and Computer Science, Ningbo University, Ningbo, China
- Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis of Zhejiang Province, Institute of Mass Spectrometry, Ningbo University, Ningbo, China
| | - Junliang Zhang
- Faculty of Electrical Engineering and Computer Science, Ningbo University, Ningbo, China
- Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis of Zhejiang Province, Institute of Mass Spectrometry, Ningbo University, Ningbo, China
| | - Tengyu Zhang
- Faculty of Electrical Engineering and Computer Science, Ningbo University, Ningbo, China
- Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis of Zhejiang Province, Institute of Mass Spectrometry, Ningbo University, Ningbo, China
| | - Huanming Wu
- Faculty of Electrical Engineering and Computer Science, Ningbo University, Ningbo, China
- Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis of Zhejiang Province, Institute of Mass Spectrometry, Ningbo University, Ningbo, China
| | - Chenlu Wang
- Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis of Zhejiang Province, Institute of Mass Spectrometry, Ningbo University, Ningbo, China
- School of Material Science and Chemical Engineering, Ningbo University, Ningbo, China
| | - Jiancheng Yu
- Faculty of Electrical Engineering and Computer Science, Ningbo University, Ningbo, China
- Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis of Zhejiang Province, Institute of Mass Spectrometry, Ningbo University, Ningbo, China
| | - Keqi Tang
- Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis of Zhejiang Province, Institute of Mass Spectrometry, Ningbo University, Ningbo, China
- School of Material Science and Chemical Engineering, Ningbo University, Ningbo, China
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19
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Brecht D, Uteschil F, Schmitz OJ. Development of an inverse low-temperature plasma ionization source for liquid chromatography/mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2021; 35:e9071. [PMID: 33625792 DOI: 10.1002/rcm.9071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 02/17/2021] [Accepted: 02/19/2021] [Indexed: 06/12/2023]
Abstract
RATIONALE An argon inverse low-temperature plasma (iLTP) ionization source for liquid chromatography/tandem mass spectrometry was developed. The iLTP is constructed from simple chromatographic supply materials and is implemented into an atmospheric pressure chemical ionization (APCI) source replacing the APCI discharge needle electrode. The newly developed ion source was coupled to an ultra-high-performance liquid chromatography (UHPLC) system. METHODS The argon iLTP was characterized by optical emission spectroscopy. The soft ionization of selected standards was also demonstrated by direct infusion experiments. In addition to the use of argon as the discharge gas, helium, synthetic air, and oxygen were used, which were tested for their performance using testosterone and vitamin D3 . RESULTS Spectroscopic measurements of the argon plasma were conducted, demonstrating the main emission band of argon metastables with corresponding energies of 11.53 eV and 11.72 eV. Infusion experiments indicate a gentle ionization by iLTP, e.g. caffeine, testosterone, reserpine, vitamin D3 , and 25-hydroxyvitamin D3 , which resulted in the corresponding protonated molecules. The splitless coupling with UHPLC (possible flow rates >1000 μL min-1 ) shows promising results in interday repeatability (n = 10) for the substances with a relative standard deviation of less than 5% and limits of detection for caffeine, testosterone, reserpine, vitamin D3 , and 25-hydroxyvitamin D3 of 10 ng L-1 , 50 ng L-1 , 500 ng L-1 , 5 μg L-1 , and 5 μg L-1 , respectively. CONCLUSIONS The argon iLTP ion source presented in this work shows promising approaches in the field of ionization of small organic molecules. The mechanism related to the discharge gas argon has not been elucidated so far and further investigations are needed. The iLTP ion source shows a very good performance with UHPLC coupling, even at increased flow rates. It could be shown that an argon iLTP can compete with the helium dielectric barrier discharge (DBD) preferred in the literature, making it a more economical choice.
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Affiliation(s)
- Dominik Brecht
- Department of Applied Analytical Chemistry, University of Duisburg-Essen, Universitaetsstrasse 5, Essen, 45141, Germany
| | - Florian Uteschil
- Department of Applied Analytical Chemistry, University of Duisburg-Essen, Universitaetsstrasse 5, Essen, 45141, Germany
| | - Oliver J Schmitz
- Department of Applied Analytical Chemistry, University of Duisburg-Essen, Universitaetsstrasse 5, Essen, 45141, Germany
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20
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Kiontke A, Roudini M, Billig S, Fakhfouri A, Winkler A, Birkemeyer C. Surface acoustic wave nebulization improves compound selectivity of low-temperature plasma ionization for mass spectrometry. Sci Rep 2021; 11:2948. [PMID: 33536450 PMCID: PMC7858570 DOI: 10.1038/s41598-021-82423-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 01/19/2021] [Indexed: 11/15/2022] Open
Abstract
Mass spectrometry coupled to low-temperature plasma ionization (LTPI) allows for immediate and easy analysis of compounds from the surface of a sample at ambient conditions. The efficiency of this process, however, strongly depends on the successful desorption of the analyte from the surface to the gas phase. Whilst conventional sample heating can improve analyte desorption, heating is not desirable with respect to the stability of thermally labile analytes. In this study using aromatic amines as model compounds, we demonstrate that (1) surface acoustic wave nebulization (SAWN) can significantly improve compound desorption for LTPI without heating the sample. Furthermore, (2) SAWN-assisted LTPI shows a response enhancement up to a factor of 8 for polar compounds such as aminophenols and phenylenediamines suggesting a paradigm shift in the ionization mechanism. Additional assets of the new technique demonstrated here are (3) a reduced analyte selectivity (the interquartile range of the response decreased by a factor of 7)—a significant benefit in non-targeted analysis of complex samples—and (4) the possibility for automated online monitoring using an autosampler. Finally, (5) the small size of the microfluidic SAWN-chip enables the implementation of the method into miniaturized, mobile LTPI probes.
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Affiliation(s)
- Andreas Kiontke
- Institute of Analytical Chemistry, University of Leipzig, Linnéstraße 3, 04103, Leipzig, Germany
| | - Mehrzad Roudini
- Leibniz Institute for Solid State and Materials Research IFW Dresden, Institute for Complex Materials (IKM), SAWLab Saxony, 01069, Dresden, Germany
| | - Susan Billig
- Institute of Analytical Chemistry, University of Leipzig, Linnéstraße 3, 04103, Leipzig, Germany
| | - Armaghan Fakhfouri
- Leibniz Institute for Solid State and Materials Research IFW Dresden, Institute for Complex Materials (IKM), SAWLab Saxony, 01069, Dresden, Germany
| | - Andreas Winkler
- Leibniz Institute for Solid State and Materials Research IFW Dresden, Institute for Complex Materials (IKM), SAWLab Saxony, 01069, Dresden, Germany
| | - Claudia Birkemeyer
- Institute of Analytical Chemistry, University of Leipzig, Linnéstraße 3, 04103, Leipzig, Germany.
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21
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Review: Miniature dielectric barrier discharge (DBD) in analytical atomic spectrometry. Anal Chim Acta 2021; 1147:211-239. [DOI: 10.1016/j.aca.2020.11.034] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 11/17/2020] [Accepted: 11/22/2020] [Indexed: 11/24/2022]
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22
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Knodel A, Foest D, Brandt S, Ahlmann N, Marggraf U, Gilbert-López B, Franzke J. Detection and Evaluation of Lipid Classes and Other Hydrophobic Compounds Using a Laser Desorption/Plasma Ionization Interface. Anal Chem 2020; 92:15212-15220. [DOI: 10.1021/acs.analchem.0c03839] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Alexander Knodel
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Bunsen-Kirchhoff-Straße 11, 44139 Dortmund, Germany
| | - Daniel Foest
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Bunsen-Kirchhoff-Straße 11, 44139 Dortmund, Germany
| | - Sebastian Brandt
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Bunsen-Kirchhoff-Straße 11, 44139 Dortmund, Germany
| | - Norman Ahlmann
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Bunsen-Kirchhoff-Straße 11, 44139 Dortmund, Germany
| | - Ulrich Marggraf
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Bunsen-Kirchhoff-Straße 11, 44139 Dortmund, Germany
| | - Bienvenida Gilbert-López
- Analytical Chemistry Research Group (FQM-323), Department of Physical and Analytical Chemistry, University of Jaén, Campus Las Lagunillas, Edif. B-3, 23071 Jaén, Spain
| | - Joachim Franzke
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Bunsen-Kirchhoff-Straße 11, 44139 Dortmund, Germany
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23
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Drees C, Schütz A, Niu G, Franzke J, Vautz W, Brandt S. Stepwise optimization of a Flexible Microtube Plasma (FµTP) as an ionization source for Ion Mobility Spectrometry. Anal Chim Acta 2020; 1127:89-97. [PMID: 32800141 DOI: 10.1016/j.aca.2020.06.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 06/05/2020] [Accepted: 06/09/2020] [Indexed: 11/24/2022]
Abstract
The ionization source is the central system of analytical devices such as mass spectrometers or ion mobility spectrometers. In this study, a recently developed flexible microtube plasma (FμTP) is applied as an ionization source for a custom-made drift tube ion mobility spectrometer (IMS) for the first time. The FµTP is based on a highly miniaturized, robust and a small-footprint dielectric barrier discharge design with an outstanding ionization efficiency. In this study, the experimental setup of the FµTP was further improved upon to achieve optimal coupling conditions in terms of the ion mobility spectrometry sensitivity and the plasma gas consumption. One major focus of this study was the adjustment of the electrical operation parameters, in particular, the high voltage amplitude, frequency and duty cycle, in order to minimize the electric field disturbances and yield higher signals. Additionally, the consumption of helium plasma gas was reduced by refining the FµTP. It was found that the ionization efficiency could be significantly enhanced by increasing the plasma high voltage and through application of a duty cycle up to 90:10. Plasma gas flows could be reduced down to 3 mL min-1 by increasing the plasma high voltage amplitude. Furthermore, a smaller wire electrode design enables the operation of the FµTP with nitrogen and clean air. Moreover, detection limits of a homologous series of ketones in the range of 330 pptv (N2-FµTP, 2-decanone) down to 20 pptv (He-FµTP, 2-octanone) could be reached in the optimized setup. To sum up, this feasibility study demonstrates the potential of the optimized FµTP as a powerful ionization source for ion mobility spectrometry especially with regard to ionization efficiency.
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Affiliation(s)
- Carolin Drees
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Bunsen-Kirchhoff-Straße 11, 44139, Dortmund, Germany
| | - Alexander Schütz
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Bunsen-Kirchhoff-Straße 11, 44139, Dortmund, Germany
| | - Guanghui Niu
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Bunsen-Kirchhoff-Straße 11, 44139, Dortmund, Germany
| | - Joachim Franzke
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Bunsen-Kirchhoff-Straße 11, 44139, Dortmund, Germany
| | - Wolfgang Vautz
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Bunsen-Kirchhoff-Straße 11, 44139, Dortmund, Germany; ION-GAS GmbH, Konrad-Adenauer-Allee 11, 44263, Dortmund, Germany
| | - Sebastian Brandt
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Bunsen-Kirchhoff-Straße 11, 44139, Dortmund, Germany.
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24
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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.
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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
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25
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Knodel A, Marggraf U, Ahlmann N, Brandt S, Foest D, Gilbert-López B, Franzke J. Standardization of Sandwich-Structured Cu–Glass Substrates Embedded in a Flexible Diode Laser–Plasma Interface for the Detection of Cholesterol. Anal Chem 2020; 92:4663-4671. [DOI: 10.1021/acs.analchem.0c00311] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Alexander Knodel
- Leibniz-Institut für Analytische Wissenschaften—ISAS—e.V., Bunsen-Kirchhoff-Straße 11, 44139 Dortmund, Germany
| | - Ulrich Marggraf
- Leibniz-Institut für Analytische Wissenschaften—ISAS—e.V., Bunsen-Kirchhoff-Straße 11, 44139 Dortmund, Germany
| | - Norman Ahlmann
- Leibniz-Institut für Analytische Wissenschaften—ISAS—e.V., Bunsen-Kirchhoff-Straße 11, 44139 Dortmund, Germany
| | - Sebastian Brandt
- Leibniz-Institut für Analytische Wissenschaften—ISAS—e.V., Bunsen-Kirchhoff-Straße 11, 44139 Dortmund, Germany
| | - Daniel Foest
- Leibniz-Institut für Analytische Wissenschaften—ISAS—e.V., Bunsen-Kirchhoff-Straße 11, 44139 Dortmund, Germany
| | - Bienvenida Gilbert-López
- Analytical Chemistry Research Group (FQM-323), Department of Physical and Analytical Chemistry, University of Jaén, Campus Las Lagunillas, Edif. B-3, 23071 Jaén, Spain
| | - Joachim Franzke
- Leibniz-Institut für Analytische Wissenschaften—ISAS—e.V., Bunsen-Kirchhoff-Straße 11, 44139 Dortmund, Germany
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26
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Vogel P, Marggraf U, Brandt S, García-Reyes JF, Franzke J. Analyte-Tailored Controlled Atmosphere Improves Dielectric Barrier Discharge Ionization Mass Spectrometry Performance. Anal Chem 2019; 91:3733-3739. [PMID: 30672695 DOI: 10.1021/acs.analchem.9b00112] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Plasma sources in atmospheric pressure soft-ionization mass spectrometry have gained significant interest in recent years. As many of these sources are used under ambient air conditions, their interaction with the surrounding atmosphere plays an important role in the ionization pathway. This study focuses on the interaction between the plasma source and the surrounding atmosphere by connecting the plasma source to the mass spectrometer using a 2 mm ID closed reactant capillary supplied by a reactant gas up to 500 mL per minute to gain a controlled atmosphere. Different reactant gases (Ar, He, O2, and N2) and reactant gas mixtures are tested with regard to the DBDI performance and then used to improve the ionization efficiency. Tailoring the controlled atmosphere for a certain analyte, for example, perfluorinated compounds, leads to significantly improved limits of detection up to 2 ppb.
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Affiliation(s)
- Pascal Vogel
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V. , Bunsen-Kirchhoff-Straße 11 , 44139 Dortmund , Germany
| | - Ulrich Marggraf
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V. , Bunsen-Kirchhoff-Straße 11 , 44139 Dortmund , Germany
| | - Sebastian Brandt
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V. , Bunsen-Kirchhoff-Straße 11 , 44139 Dortmund , Germany
| | - Juan F García-Reyes
- Analytical Chemistry Research Group , University of Jaén , Campus Las Lagunillas , 23071 Jaén , Spain
| | - Joachim Franzke
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V. , Bunsen-Kirchhoff-Straße 11 , 44139 Dortmund , Germany
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