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Ilbeigi V, Valadbeigi Y, Moravsky L, Matejčík Š. Formic Acid as a Dopant for Atmospheric Pressure Chemical Ionization for Negative Polarity of Ion Mobility Spectrometry and Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:2051-2060. [PMID: 37498108 DOI: 10.1021/jasms.3c00225] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
Formic acid (FA) is introduced as a potent dopant for atmospheric pressure chemical ionization (APCI) for ion mobility spectrometry (IMS) and mass spectrometry (MS). The mechanism of chemical ionization with the FA dopant was studied in the negative polarity using a corona discharge (CD)-IMS-MS technique in air. Standard reactant ions of the negative polarity present in air are O2-·(CO2)n·(H2O)m (m = 0, 1 and n = 1, 2) clusters. Introduction of the FA dopant resulted in the production of HCOO-·FA reactant ions. The effect of the FA dopant on the APCI of different classes of compounds was investigated, including plant hormones, pesticides, acidic drugs, and explosives. FA dopant APCI resulted in deprotonation and/or adduct ion formation, [M - H]- and [M + HCOO]-, respectively. Supporting density functional theory (DFT) calculations showed that the ionization mechanism depended on the gas-phase acidity of the compounds. FA dopant APCI led to the improvement of detection sensitivity, suppression of fragmentation, and changes in the ion mobilities of the analyte ions for analytes with suitable molecular structures and gas acidity.
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Affiliation(s)
- Vahideh Ilbeigi
- Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava, Mlynská dolina F2, 84248 Bratislava, Slovakia
| | - Younes Valadbeigi
- Department of Chemistry, Faculty of Science, Imam Khomeini International University, 34148-96818 Qazvin, Iran
| | - Ladislav Moravsky
- Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava, Mlynská dolina F2, 84248 Bratislava, Slovakia
| | - Štefan Matejčík
- Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava, Mlynská dolina F2, 84248 Bratislava, Slovakia
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Schaefer C, Schlottmann F, Kirk AT, Zimmermann S. Influence of Sample Gas Humidity on Product Ion Formation in High Kinetic Energy Ion Mobility Spectrometry (HiKE-IMS). JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:1048-1060. [PMID: 35594571 DOI: 10.1021/jasms.2c00099] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
High Kinetic Energy Ion Mobility Spectrometers (HiKE-IMS) chemically ionize gaseous samples via reactant ions and separate the generated ions by their motion in a neutral gas under the influence of an electric field. Operation at reduced pressures of 10-40 mbar allows for reaching high reduced electric field strengths (E/N) of up to 120 Td. At these high E/N, the generated ions gain the namesake high kinetic energies, leading to a decrease in cluster size of the reactant ions by increasing the reaction rate of collision-induced cluster dissociation of hydrates. In positive ion polarity and in purified air, H3O+(H2O)n, NO+(H2O)n, and O2+•(H2O)p are the most abundant reactant ions. In this work, we investigate the effect of varying sample gas humidity on product ion formation for several model substances. Results show that increasing the sample gas humidity at high E/N of 120 Td shifts product ion formation from a charge transfer dominated reaction system to a proton transfer dominated reaction system. For HiKE-IMS operated at high E/N, the reduction in cluster size of reactant ions allows ionization of analytes with low proton affinity even at high relative humidity in the sample gas of RH = 75% at 303.15 K and 1013.25 hPa. In contrast to conventional IMS, where increasing the sample gas humidity inhibits ionization for various analytes, increasing sample gas humidity in HiKE-IMS operated at 120 Td is actually beneficial for ionization yield of most analytes investigated in this work as it increases the number of H3O+(H2O)n.
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Affiliation(s)
- Christoph Schaefer
- Department of Sensors and Measurement Technology, Institute of Electrical Engineering and Measurement Technology, Leibniz University Hannover, Appelstrasse 9A, 30167 Hannover, Germany
| | - Florian Schlottmann
- Department of Sensors and Measurement Technology, Institute of Electrical Engineering and Measurement Technology, Leibniz University Hannover, Appelstrasse 9A, 30167 Hannover, Germany
| | - Ansgar T Kirk
- Department of Sensors and Measurement Technology, Institute of Electrical Engineering and Measurement Technology, Leibniz University Hannover, Appelstrasse 9A, 30167 Hannover, Germany
| | - Stefan Zimmermann
- Department of Sensors and Measurement Technology, Institute of Electrical Engineering and Measurement Technology, Leibniz University Hannover, Appelstrasse 9A, 30167 Hannover, Germany
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Spesyvyi A, Lacko M, Dryahina K, Smith D, Španěl P. Ligand Switching Ion Chemistry: An SIFDT Case Study of the Primary and Secondary Reactions of Protonated Acetic Acid Hydrates with Acetone. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:2251-2260. [PMID: 34283585 DOI: 10.1021/jasms.1c00174] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A study was performed of the reactions of protonated acetic acid hydrates, CH3COOHH+(H2O)n, with acetone molecules, CH3COCH3, using a selected ion flow-drift tube (SIFDT). The rationale for this study is that hydrated protonated organic molecules are major product ions in secondary electrospray ionization mass spectrometry (SESI-MS) and ion mobility spectrometry (IMS). Yet the formation and reactivity of these hydrates are only poorly understood, and kinetics data are only sparse. The existing SIFDT instrument in our laboratory was upgraded to include an octupole ion guide and a separate drift tube by which hydrated protonated ions can be selectively injected into the drift tube reactor and their reactions with molecules studied under controlled conditions. This case study shows that, in these hydrated ion reactions with acetone molecules, the dominant reaction process is ligand switching producing mostly proton-bound dimer ions (CH3COCH3)H+(CH3COOH), with minor branching into (CH3COCH3)H+(H2O). This switching reaction was observed to proceed at the collisional rate, while other studied hydrated ions reacted more slowly. An attempt is made to understand the reaction mechanisms and the structures of the reaction intermediate ions at the molecular level. Secondary switching reactions of the asymmetric proton-bound dimer ions lead to a formation of strongly bound symmetrical dimers (CH3COCH3)2H+, the terminating ion in this ion chemistry. These results strongly suggest that, in SESI-MS and IMS, the presence of a polar compound, like acetone in exhaled breath, can suppress the analyte ions of low concentration compounds like acetic acid thus compromising their quantification.
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Affiliation(s)
- Anatolii Spesyvyi
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 2155/3, 18223 Prague 8, Czech Republic
| | - Michal Lacko
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 2155/3, 18223 Prague 8, Czech Republic
- Faculty of Mathematics and Physics, Charles University, V Holešovičkách 747/2, 18000 Prague 8, Czech Republic
| | - Kseniya Dryahina
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 2155/3, 18223 Prague 8, Czech Republic
| | - David Smith
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 2155/3, 18223 Prague 8, Czech Republic
| | - Patrik Španěl
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 2155/3, 18223 Prague 8, Czech Republic
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Valadbeigi Y, Ilbeigi V, Khodabandeh Z. Formation of anionic clusters of triols in the atmospheric pressure chemical ionization source: An ion mobility spectrometry and theoretical study. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.138738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Brendel R, Rohn S, Weller P. Nitrogen monoxide as dopant for enhanced selectivity of isomeric monoterpenes in drift tube ion mobility spectrometry with 3H ionization. Anal Bioanal Chem 2021; 413:3551-3560. [PMID: 33839916 PMCID: PMC8105222 DOI: 10.1007/s00216-021-03306-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/27/2021] [Accepted: 03/22/2021] [Indexed: 12/22/2022]
Abstract
The ion mobility spectra of the isomeric monoterpenes α-pinene, β-pinene, myrcene, and limonene in drift tube ion mobility spectrometry (IMS) with 3H radioactive ionization are highly similar and difficult to distinguish. The aim of this work was to enhance the selectivity of IMS by the addition of nitrogen monoxide (NO) as dopant and to investigate the underlying changes in ion formation responsible for the modified ion signals observed in the ion mobility spectra. Even though 3H-based-IMS systems have been used in hyphenation with gas chromatography (GC) for profiling of volatile organic compounds (VOCs), the investigation of ion formation still remains challenging and was exemplified by the investigated monoterpenes. Nonetheless, the formation of monomeric, dimeric, and trimeric ion clusters could be tentatively confirmed by a mass-to-mobility correlation and the highly similar pattern of ion signals in the monomer region was attributed to isomerization mechanisms potentially occurring after proton transfer reactions. The addition of NO as dopant could finally lead to the formation of additional product ions and increased the selectivity of IMS for the investigated monoterpenes as confirmed by principal component analysis (PCA). The discrimination of monoterpenes in the volatile profile is highly relevant in the quality control of hops and was given as the example for application. The results indicate that additional product ions were obtained by the formation of NO+ adduct ions, next to hydride abstraction, charge transfer, or fragmentation reactions. This approach can potentially leverage selectivity issues in VOC profiling of complex matrices, such as food matrices or raw materials in combination with chemometric pattern recognition techniques.
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Affiliation(s)
- Rebecca Brendel
- Institute for Instrumental Analytics and Bioanalytics, Mannheim University of Applied Sciences, Paul-Wittsack-Strasse 10, 68163, Mannheim, Germany.,Hamburg School of Food Science, University of Hamburg, Grindelallee 117, 20146, Hamburg, Germany
| | - Sascha Rohn
- Hamburg School of Food Science, University of Hamburg, Grindelallee 117, 20146, Hamburg, Germany.,Department of Food Chemistry and Analysis, Institute of Food Technology and Food Chemistry, Technische Universität Berlin, TIB 4/3-1, Gustav-Meyer-Allee 25, 13355, Berlin, Germany
| | - Philipp Weller
- Institute for Instrumental Analytics and Bioanalytics, Mannheim University of Applied Sciences, Paul-Wittsack-Strasse 10, 68163, Mannheim, Germany.
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Valadbeigi Y, Ilbeigi V. Using gas-phase chloride attachment for selective detection of morphine in a morphine/codeine mixture by ion mobility spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2021; 35:e9044. [PMID: 33410177 DOI: 10.1002/rcm.9044] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 12/18/2020] [Accepted: 01/05/2021] [Indexed: 06/12/2023]
Abstract
RATIONALE Morphine and codeine are two important compounds of the opiate family that have vast applications in medicine. Several techniques have been reported for the determination of these opiates. Although ion mobility spectrometry (IMS) in positive ion mode can be applied for detection of both morphine and codeine, this technique on its own cannot detect a mixture of these two compounds because of the overlapping of their peaks. METHODS An IMS instrument equipped with a corona discharge ion source operating in negative ion mode was used for the detection of anionic clusters of morphine and codeine. In normal negative ion mode, NOx - , CO3 - , and On - act as the main reactant ions (RIs) which can deprotonate the analytes. We also used chloroform as a dopant to produce Cl- as an alternative RI. RESULTS Morphine has a phenolic and an alcoholic OH group, while codeine bears only an alcoholic OH group. Because the phenolic OH group is more acidic, only morphine is deprotonated in negative ion mode in a morphine/codeine mixture. Furthermore, since morphine has two OH groups that can act as hydrogen-bond donors, it acts as an anion receptor. Hence, in the presence of chloroform where Cl- acts as the RI, morphine traps the Cl- anion to form a morphine-Cl- (Mor.Cl- ) adduct ion, while because of its structure codeine does not have this capability. CONCLUSIONS Using the difference in the structures of morphine and codeine, two ionization methods were proposed for selective detection of morphine. Morphine is more acidic than codeine and has greater anion-receiving capability than codeine. Hence, it can both be deprotonated and form a adduct anion with Cl- . The Cl- attachment method is recommended for measurements at ambient temperature.
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Affiliation(s)
- Younes Valadbeigi
- Department of Chemistry, Faculty of Science, Imam Khomeini International University, Qazvin, Iran
| | - Vahideh Ilbeigi
- TOF Tech. Pars Company, Isfahan Science & Technology Town, Isfahan, Iran
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Valadbeigi Y, Ilbeigi V, Mamozai W, Soleimani M. Rapid and simple determination of gabapentin in urine by ion mobility spectrometry. J Pharm Biomed Anal 2021; 197:113980. [PMID: 33636645 DOI: 10.1016/j.jpba.2021.113980] [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: 10/18/2020] [Revised: 02/12/2021] [Accepted: 02/12/2021] [Indexed: 10/22/2022]
Abstract
Gabapentin is a pharmacological agent used in the treatment of epileptic seizures. In this work, a fast method is proposed for determination of gabapentin in urine by ion mobility spectrometry (IMS) without any extraction and derivatization. ZnCl2 was used as an effective protein precipitating reagent to remove the urine proteins. It was found that urea content of urine interferes with detection of gabapentin by IMS. By applying a delay on the carrier gas flow after injection of the sample, we could solve the urea interference to achieve gabapentin signal recovery of ∼70% in urine relative to that in water.
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Affiliation(s)
- Younes Valadbeigi
- Department of Chemistry, Faculty of Science, Imam Khomeini International University, Qazvin, Iran.
| | - Vahideh Ilbeigi
- TOF Tech. Pars Company, Isfahan Science & Technology Town, Isfahan, Iran
| | - Wafiullah Mamozai
- Department of Chemistry, Faculty of Science, Imam Khomeini International University, Qazvin, Iran
| | - Majid Soleimani
- Department of Chemistry, Faculty of Science, Imam Khomeini International University, Qazvin, Iran
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Valadbeigi Y, Ilbeigi V, Mirsharifi MS. Mechanism of atmospheric pressure chemical ionization of morphine, codeine, and thebaine in corona discharge-ion mobility spectrometry: Protonation, ammonium attachment, and carbocation formation. JOURNAL OF MASS SPECTROMETRY : JMS 2020; 55:e4586. [PMID: 32720743 DOI: 10.1002/jms.4586] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/30/2020] [Accepted: 06/05/2020] [Indexed: 06/11/2023]
Abstract
Atmospheric pressure chemical ionizations (APCIs) of morphine, codeine, and thebaine were studied in a corona discharge ion source using ion mobility spectrometry (IMS) at temperature range of 100°C-200°C. Density functional theory (DFT) at the B3LYP/6-311++G(d,p) and M062X/6-311++G(d,p) levels of theory were used to interpret the experimental data. It was found that in the presence of H3 O+ as reactant ion (RI), ionization of morphine and codeine proceeds via both the protonation and carbocation formation, whereas thebaine participates only in protonation. Carbocation formation (fragmentation) was diminished with decrease in the temperature. At lower temperatures, proton-bound dimers of the compounds were also formed. Ammonia was used as a dopant to produce NH4 + as an alternative RI. In the presence of NH4 + , proton transfer from ammonium ion to morphine, codeine, and thebaine was the dominant mechanism of ionization. However, small amount of ammonium attachment was also observed. The theoretical calculations showed that nitrogen atom of the molecules is the most favorable proton acceptor site while the oxygen atoms participate in ammonium attachment. Furthermore, formation of the carbocations is because of the water elimination from the protonated forms of morphine and codeine.
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Affiliation(s)
- Younes Valadbeigi
- Department of Chemistry, Faculty of Science, Imam Khomeini International University, Qazvin, Iran
| | - Vahideh Ilbeigi
- TOF Tech. Pars Company, Isfahan Science & Technology Town, Isfahan, Iran
| | - Maryam S Mirsharifi
- Department of Chemistry, Faculty of Science, Imam Khomeini International University, Qazvin, Iran
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Valadbeigi Y, Bayat S, Ilbeigi V. A Novel Application of Dopants in Ion Mobility Spectrometry: Suppression of Fragment Ions of Citric Acid. Anal Chem 2020; 92:7924-7931. [DOI: 10.1021/acs.analchem.0c01318] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Younes Valadbeigi
- Department of Chemistry, Faculty of Science, Imam Khomeini International University, Qazvin, Iran
| | - Sahar Bayat
- Department of Chemistry, Faculty of Science, Imam Khomeini International University, Qazvin, Iran
| | - Vahideh Ilbeigi
- TOF Tech. Pars Company, Isfahan Science & Technology Town, Isfahan, Iran
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Valadbeigi Y, Azizmohammadi S, Ilbeigi V. Small Host–Guest Systems in the Gas Phase: Tartaric Acid as a Host for both Anionic and Cationic Guests in the Atmospheric Pressure Chemical Ionization Source of Ion Mobility Spectrometry. J Phys Chem A 2020; 124:3386-3397. [DOI: 10.1021/acs.jpca.0c00118] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Younes Valadbeigi
- Department of Chemistry, Faculty of Science, Imam Khomeini International University, Qazvin, Iran
| | - Sima Azizmohammadi
- Department of Chemistry, Faculty of Science, Imam Khomeini International University, Qazvin, Iran
| | - Vahideh Ilbeigi
- TOF Tech. Pars Company, Isfahan Science & Technology Town, Isfahan, Iran
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