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41 results on '"Bouza, Marcos"'

5. Measuring the mass of an electron: an undergraduate laboratory experiment with high resolution mass spectrometry

Author

Bouza Marcos, Gilbert-López Bienvenida, García-Reyes Juan Francisco, and Rodríguez Ortega Pilar Gema

Subjects
analytical chemistry, instrumental application, laboratory activity, mass spectrometry, Chemistry, QD1-999
Abstract

High-resolution mass spectrometry (HRMS) has become increasingly affordable and user-friendly. Its potential spans a wide range of applications and experiments including the measurement of accurate masses, supporting the elucidation of elemental compositions and the identification of unknown compounds. To illustrate the main features of mass spectrometry, and particularly, of HRMS, we have designed and implemented a 3-h laboratory experiment using direct infusion electrospray HRMS analysis of non-steroidal anti-inflammatory drugs (e.g., ibuprofen or naproxen) solutions, acquiring full-scan spectra in both positive and negative ionization modes. The experimental accurate mass measurements (m/z values) of selected characteristic fragment ions -so called twin ions, with common elemental composition in both ionization modes but with different charge, allow the indirect measurement of the mass of an electron with relative errors below 5% with respect to the accepted IUPAC value (0.00055 Da). The experiment demonstrates how powerful and useful HRMS can be for research challenges often encountered during undergraduate or graduate research projects as well as for addressing undergraduate level general chemistry problems that provide the opportunity to discuss aspects related to the Nature of Science in an analytical chemistry context (such as measurement precision and accuracy).

Published
2021
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13. Liquid chromatography‐dielectric barrier discharge ionization mass spectrometry for the analysis of neutral lipids of archaeological interest

Author

Bouza, Marcos, primary, García‐Martínez, Julio, additional, Gilbert‐López, Bienvenida, additional, Moreno‐González, David, additional, Rocío‐Bautista, Priscilla, additional, Parras‐Guijarro, David, additional, Sánchez‐Vizcaino, Alberto, additional, Brandt, Sebastian, additional, García‐Reyes, Juan F., additional, Molina‐Díaz, Antonio, additional, and Franzke, Joachim, additional

Published
2022
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14. Dielectric Barrier Discharge Ionization with different sample introduction formats for small molecule applications

Author

Rocío-Bautista, Priscilla, Bouza, Marcos, Bartella, Lucia, Brandt, Sebastian, Franzke, Joachim, Lazarou, Constantinos, Gilbert-López, Bienvenida, and García-Reyes, Juan F.

Subjects
plasma, mass spectrometry, ionization, SciX 2022, plasma, mass spectrometry, ionization
Abstract

Dielectric barrier discharges (DBD) are used as soft ionization sources for mass spectrometers (MS) or ion mobility spectrometers, enabling excellent possibilities for analytical applications. Detailed studies have increased knowledge about fundamental discharge mechanisms in noble gas discharges at atmospheric pressure, which have led to further improvements in the use of these discharges. The present communication describes different sample introduction formats using DBD based-devices as ionization tools. These devices configurations are: dielectric barrier discharge ionization, low-temperature plasma and flexible micro-tube plasma. Those devices were compared with more conventional sample introduction interfaces, such as electrospray, paper spray or atmospheric pressure chemical ionization., Oral presentation at SciX 2022 conference, Liverpool UK

Published
2022
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19. Effect of dielectric barrier discharge (DBD) electrode configuration in the internal energy distribution of generated ions

Author

Rocío-Bautista, Priscilla, García-Martínez, Julio, Gilbert-López, Bienvenida, Anastassiou, Charalambos, Brandt, Sebastian, Molina-Díaz, Antonio, García-Reyes, Juan F, Franzke, Joachim, and Bouza, Marcos

Subjects
Physics::Plasma Physics, Plasma, discharge, ionization, spectrometry
Abstract

Dielectric barrier discharges are one of the most common plasma-based ion sources in mass spectrometry. The versatility in design and the ability to miniaturize the ion sources in addition to the observed performance have made them popular. Low-temperature plasma (LTP), dielectric barrier discharge ionization (DBDI), or flexible microtube plasma (FµTP) are three examples of high-frequency alternative current operated plasmas. The different designs should involve different energies to the ions during the gas-phase ionization. As shown in the literature, Thermometer ions are the favorite molecules to study the internal energy deposited on the ions during positive ion mode ionization. Here, we proposed the investigation of different DBDI ion sources designs internal energy distributions evaluation.

Published
2021
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25. Measuring the mass of an electron: an undergraduate laboratory experiment with high resolution mass spectrometry.

Author

Bouza, Marcos, Gilbert-López, Bienvenida, García-Reyes, Juan Francisco, and Rodríguez Ortega, Pilar Gema

Subjects
MASS spectrometry, ELECTROSPRAY ionization mass spectrometry, ANALYTICAL chemistry, MASS measurement, DAUGHTER ions, ELECTRONS
Abstract

High-resolution mass spectrometry (HRMS) has become increasingly affordable and user-friendly. Its potential spans a wide range of applications and experiments including the measurement of accurate masses, supporting the elucidation of elemental compositions and the identification of unknown compounds. To illustrate the main features of mass spectrometry, and particularly, of HRMS, we have designed and implemented a 3-h laboratory experiment using direct infusion electrospray HRMS analysis of non-steroidal anti-inflammatory drugs (e.g., ibuprofen or naproxen) solutions, acquiring full-scan spectra in both positive and negative ionization modes. The experimental accurate mass measurements (m/z values) of selected characteristic fragment ions -so called twin ions, with common elemental composition in both ionization modes but with different charge, allow the indirect measurement of the mass of an electron with relative errors below 5% with respect to the accepted IUPAC value (0.00055 Da). The experiment demonstrates how powerful and useful HRMS can be for research challenges often encountered during undergraduate or graduate research projects as well as for addressing undergraduate level general chemistry problems that provide the opportunity to discuss aspects related to the Nature of Science in an analytical chemistry context (such as measurement precision and accuracy). [ABSTRACT FROM AUTHOR]

Published
2022
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31. Robotic Surface Analysis Mass Spectrometry (RoSA-MS) of Three-Dimensional Objects

Author

Li, Anyin, Paine, Martin R. L., Zambrzycki, Stephen, Stryffeler, Rachel B., Wu, Jason, Bouza, Marcos, Huckaby, Jake, Chang, Chu-Yin, Kumar, Manoj, Mukhija, Piyoosh, and Ferna´ndez, Facundo M.

Abstract

Many technologies currently exist that are capable of analyzing the surface of solid samples under ambient or vacuum conditions, but they are typically limited to smooth, planar surfaces. Those few that can be applied to nonplanar surfaces, however, require manual sampling and a high degree of human intervention. Herein, we describe a new platform, Robotic Surface Analysis Mass Spectrometry (RoSA-MS), for direct surface sampling of three-dimensional (3D) objects. In RoSA-MS, a sampling probe is attached to a robotic arm that has 360° rotation through 6 individual joints. A 3D laser scanner, also attached to the robotic arm, generates a digital map of the sample surface that is used to direct a probe to specific (x, y, z) locations. The sampling probe consists of a spring-loaded needle that briefly contacts the object surface, collecting trace amounts of material. The probe is then directed at an open port liquid sampling interface coupled to the electrospray ion source of a mass spectrometer. Material on the probe tip is dissolved by the solvent flow in the liquid interface and mass analyzed with high mass resolution and accuracy. The surface of bulky, nonplanar objects can thus be probed to produce chemical maps at the molecular level. Applications demonstrated herein include the examination of food sample surfaces, lifestyle chemistry, and chemical reactions on curved substrates. The modular design of this system also allows for modifications to the sampling probe and the ionization source, thereby expanding the potential of RoSA-MS for a great diversity of applications.

Published
2024
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38. Front Cover: A Shared Prebiotic Formation of Neopterins and Guanine Nucleosides from Pyrimidine Bases (Chem. Eur. J. 39/2022).

Author

Menor‐Salván, César, Burcar, Bradley T., Bouza, Marcos, Fialho, David M., Fernández, Facundo M., and Hud, Nicholas V.

Subjects
PYRIMIDINE nucleosides, GUANINE, ORIGIN of life, PTERIDINES, INULIN
Abstract

Keywords: pterins; guanosine; origins of life; RNA world; phosphorylation EN pterins guanosine origins of life RNA world phosphorylation 1 1 1 07/13/22 20220711 NES 220711 B Guanosine and pterins are depicted as the constellation Gemini b . However, like Pollux from Greek mythology, guanosine would not have been born alone - pterins would have been formed in equal (or, in this case, even in major) parts through prebiotic reactions. Pterins, guanosine, origins of life, RNA world, phosphorylation. [Extracted from the article]

Published
2022
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39. Ambient (desorption/ionization) mass spectrometry methods for pesticide testing in food: a review

Author

Beneito-Cambra, Miriam, Gilbert-López, Bienvenida, Moreno-González, David, Bouza, Marcos, Franzke, Joachim, García-Reyes, Juan F., and Molina-Díaz, Antonio

Subjects
2. Zero hunger
Abstract

Ambient mass spectrometry refers to the family of techniques that allows ions to be generated from condensed phase samples under ambient conditions and then, collected and analysed by mass spectrometry. One of their key advantages rely on the ability to allow the interrogation of samples with minimal to no sample workup. This feature map well against the requirements of food safety testing, in particular, those related with the fast determination of pesticide residues in foodstuffs. This review addresses the application of different ambient ionization methods for the qualitative and (semi)quantitative determination of pesticides in foods, attending to the different specific methods used and their ionization mechanisms. The more popular techniques used are those commercially available including Desorption Electrospray Ionization (DESI-MS), direct analysis on real time (DART-MS), paper spray (PS-MS) and low-temperature plasma (LTP-MS). Several applications described with ambient MS have reported limits of quantitation approaching reference methods, typically based on LC-MS and generic sample extraction procedures. Some of them has been combined with portable mass spectrometers thus allowing “in situ” analysis. In addition, these techniques have the ability to map surfaces (Ambient MS imaging) to unravel the distribution of the agrochemicals on the crop.

40. Ambient (desorption/ionization) mass spectrometry methods for pesticide testing in food: a review

Author

Beneito-Cambra, Miriam, Gilbert-López, Bienvenida, Moreno-González, David, Bouza, Marcos, Franzke, Joachim, García-Reyes, Juan F., and Molina-Díaz, Antonio

Subjects
2. Zero hunger
Abstract

Ambient mass spectrometry refers to the family of techniques that allows ions to be generated from condensed phase samples under ambient conditions and then, collected and analysed by mass spectrometry. One of their key advantages rely on the ability to allow the interrogation of samples with minimal to no sample workup. This feature map well against the requirements of food safety testing, in particular, those related with the fast determination of pesticide residues in foodstuffs. This review addresses the application of different ambient ionization methods for the qualitative and (semi)quantitative determination of pesticides in foods, attending to the different specific methods used and their ionization mechanisms. The more popular techniques used are those commercially available including Desorption Electrospray Ionization (DESI-MS), direct analysis on real time (DART-MS), paper spray (PS-MS) and low-temperature plasma (LTP-MS). Several applications described with ambient MS have reported limits of quantitation approaching reference methods, typically based on LC-MS and generic sample extraction procedures. Some of them has been combined with portable mass spectrometers thus allowing “in situ” analysis. In addition, these techniques have the ability to map surfaces (Ambient MS imaging) to unravel the distribution of the agrochemicals on the crop.

41. A Shared Prebiotic Formation of Neopterins and Guanine Nucleosides from Pyrimidine Bases.

Author

Menor-Salván C, Burcar BT, Bouza M, Fialho DM, Fernández FM, and Hud NV

Subjects
Guanine chemistry, Neopterin, Purine Nucleosides, Pyrimidines, Nucleosides chemistry, Prebiotics
Abstract

Invited for the cover of this issue are the groups of César Menor-Salván, Facundo Fernández and Nicholas V. Hud at the University of Alcala and the Georgia Institute of Technology. The image depicts the authors contemplating the origin of pterins and guanosine nucleosides from a common precursor, with the art-gallery setting embodying their feeling that the common synthetic pathways of these molecules in both the prebiotic world and in biochemistry is a natural work of (chemical) art. Read the full text of the article at 10.1002/chem.202200714., (© 2022 Wiley-VCH GmbH.)

Published
2022
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