Examinando por Autor "Bouza, Marcos"
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Ítem Ambient (desorption/ionization) mass spectrometry methods for pesticide testing in food: a reviewBeneito-Cambra, Miriam; Gilbert-López, Bienvenida; Moreno-González, David; Bouza, Marcos; Franzke, Joachim; García-Reyes, Juan F.; Molina-Díaz, AntonioAmbient 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 relies on their ability to allow the analysis of samples with minimal to no sample workup. This feature maps well to the requirements of food safety testing, in particular, those related to the fast determination of pesticide residues in foods. This review discusses the application of different ambient ionization methods for the qualitative and (semi)quantitative determination of pesticides in foods, with the focus on different specific methods used and their ionization mechanisms. More popular techniques used are those commercially available including desorption electrospray ionization (DESI-MS), direct analysis on real time (DART-MS), paper spray (PSMS) and low-temperature plasma (LTP-MS). Several applications described with ambient MS have reported limits of quantitation approaching those of reference methods, typically based on LC-MS and generic sample extraction procedures. Some of them have 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 agrochemicals on crops.Ítem Ambient (desorption/ionization) mass spectrometry methods for pesticide testing in food: a review(Royal Chemical Society, 2020-08-02) Beneito-Cambra, Miriam; Gilbert-López, Bienvenida; Moreno-González, David; Bouza, Marcos; Franzke, Joachim; García-Reyes, J. Francisco; Molina-Díaz, AntonioAmbient 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 relies on their ability to allow the analysis of samples with minimal to no sample workup. This feature maps well to the requirements of food safety testing, in particular, those related to the fast determination of pesticide residues in foods. This review discusses the application of different ambient ionization methods for the qualitative and (semi)quantitative determination of pesticides in foods, with the focus on different specific methods used and their ionization mechanisms. 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 those of reference methods, typically based on LC-MS and generic sample extraction procedures. Some of them have 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 agrochemicals on crops.Ítem Aplicaciones de la descarga de barrera dieléctrica como fuente de ionización en cromatografía líquida/espectrometría de masas(2024-10-25) García-Martínez, Julio; Gilbert-López, Bienvenida; Bouza, Marcos; Universidad de Jaén. Departamento de Química Física y AnalíticaLas técnicas cromatografía líquida (LC) y cromatografía de gases (GC) acopladas a espectrometría de masas (MS), son dos de las más empleadas en la determinación de contaminantes orgánicos en alimentos. La demanda constante de adaptación de los métodos analíticos a los cambios normativos buscando la protección de la salud de los consumidores conlleva una constante evolución de las técnicas de análisis. En ese sentido, la necesidad de flexibilizar la capacidad de análisis, concretamente de LC- MS, ha propiciado el desarrollo de nuevas fuentes de ionización, siendo un ejemplo de ello las basadas en plasmas generados por descarga de barrera dieléctrica (DBD). El objetivo principal de la presente Tesis Doctoral consistió en la profundización y utilización de los mecanismos de ionización de las fuentes basadas en DBD acopladas a LC-MS; permitiendo el desarrollo de nuevos métodos analíticos para la determinación de compuestos de diversa índole en distintos tipos de matrices. Liquid chromatography (LC) and gas chromatography (GC) coupled with mass spectrometry (MS) represent two of the most commonly employed analytical techniques for determining organic contaminants in food. The constant demand to adapt methods to regulatory updates for consumer health protection entails continual evolution of analytical techniques. In this context, the need to enhance the flexibility of LC-MS analysis has driven the development of new ionization sources, such as those based on plasmas generated by dielectric barrier discharge (DBD). The main objective of this PhD Thesis was to deepen and utilize the ionization mechanisms of DBD-based sources coupled to LC-MS. This has enabled the development of new analytical methods employing LC-DBDI-MS coupling for the determination of various compounds in different matrices.Ítem Direct analysis of olive oil and other vegetable oils by mass spectrometry: a reviewBeneito-Cambra, Miriam; Moreno-González, David; García-Reyes, Juan F.; Bouza, Marcos; Bienvenida Gilbert-López, Bienvenida; Molina Díaz, AntonioVirgin olive oil (VOO) is a highly valued vegetable oil often subjected to fraud practices such as adulteration with lower prized oils such as seed oils and refined olive oil. Thus, there is a need to provide rapid tools that allow high-throughput authentication and quality control of VOO as well as other valued oils. Mass spectrometry offers unique features -such as specificity, sensitivity and speed of analysis-that map well against this challenge, either those based on atmospheric pressure ionization methods (ESI and APCI) or those occurring under vacuum conditions such as MALDI for nonvolatile species or headspace sampling-mass spectrometry using electron impact ionization (HS-MS) or chemical ionization (proton transfer reaction mass spectrometry (PTR-MS) and selected ion flow tube mass spectrometry (SIFT-MS)) for volatile fraction analysis. In addition, more recent atmospheric pressure methods (Ambient MS) enable direct analysis with minor or even no sample manipulation. The aim of this article is to provide a critical overview on all these methods and their potential use for vegetable oil characterization, highlighting the strengths and weaknesses of the different