Use of high resolution mass/mass spectrometry for the investigation of food safety and environmental impact of organic emerging contaminants

A presente tese céntrase no desenvolvemento e optimización de metodoloxías analíticas, principalmente baseadas na espectrometría de masas en tándem e de alta resolución, para a determinación de contaminantes orgánicos emerxentes e o seu impacto ambiental, así como a investigación no ámbito da seguridade alimentaria. No compartimento ambiental, as dúas clases de contaminantes orgánicos estudiados foron os funxicidas e os filtros UV, xa que son susceptibles de alcanzar as augas superficiais debido ao seu modo de emprego. Ademais de metodoloxías para a identificación e cuantificación destes compostos en mostras de augas, propóñense métodos de fotodegradación eficientes para a súa eliminación. A cromatografía acoplada a espectrometría de masas de alta resolución co modo de adquisición SWATH foi empregada tamén para a realización de analíticas non-targeted para a identificación de produtos de degradación. En canto ao ámbito alimentario, desenvolveuse unha metodoloxía de determinación e cuantificación dun amplo grupo de micotoxinas nun cento de mostras de alimentación animal. Identificáronse tamén formas modificadas dos compostos de interese empregando o modo de adquisición SWATH

Combined (d)SPE-QuEChERS Extraction of Mycotoxins in Mixed Feed Rations and Analysis by High Performance Liquid Chromatography-High-Resolution Mass Spectrometry

The objective of this work was the development of a methodology capable of simultaneously determine 26 mycotoxins in mixed feed rations collected in 20 dairy farms. A sample preparation methodology based on a combination of (d)SPE and QuEChERS extractions was used. Liquid chromatography-high resolution mass spectrometry was employed for both identification and quantification purposes. To this respect, a powerful workflow based on data-independent acquisition, consisting of fragmenting all precursor ions entering the mass spectrometer in narrow m/z isolation windows (SWATH), was implemented. SWATH data file then contains all the information that would be acquired in a multitude of different experimental approaches in a single all-encompassing dataset. Analytical method performance was evaluated in terms of linearity, repeatability and matrix effect. Relative recoveries were also measured, giving values above 80% for most compounds. Matrix-matched calibration was carried out and enabled reaching the low ng mL−1 level for many mycotoxins. The observed matrix effect, in most cases suppressive, reached even values higher than 60%. The repeatability was also adequate, showing a relative standard deviation lower than 10%. All unified samples analyzed showed co-occurrence of two or more mycotoxins, recurrently zearalenone, fumonisin B1, and β-zearalenol, with an occurrence frequency ranging from 60% to 90%This work was supported by the CONECTA-PEME GALAC project IN852A 2016/103. This work was also supported by the project IGDC13-1E-2026 (Infrastructure Program, MINECO, Spain). The authors belong to the Galician Competitive Research Groups GPC 2017/04 and GPC IN607B 2019/13, and to the CRETUS Strategic Partnership (ED431E 2018/01). All these programs are co-funded by FEDER (UE)S