Study of the matrix effect of table and wine grapes using GC-QqQ-MS

The matrix effect in analytics is known as the variation in the response of the analytical system, induced by the presence of some components of the matrix (coextractives) in which the analyte is found. This effect occurs throughout the entire analytical determination. In separative techniques, the most common case is the coelution of the analyte with the matrix components. In other cases, the characteristics of the analytical system also participate in this effect. In gas chromatography, these two aspects are involved: how the matrix influences the degradation of compounds at the injection port and their ability throughout the chromatographic run. The study of it is contemplated in the validation of analytical methodologies. There are different ways of approaching the study of the matrix effect, ranging from statistical methods to methods based on instrumental determinations. According to the SANTE document, the matrix effect can be studied by analyzing the analytical sensitivity through the quotient of the slopes of the calibration curves prepared in the matrix and solvent, respectively. Using the equation below, complementary information is obtained when its sign and module are analyzed, classifying the effect as low, moderate, and high and, in turn, signal suppression/increase. EM (%) = ((matrix matched calibration slope)/(solvent calibration slope)-1) ×100 The present work studies the matrix effect that occurs using gas chromatography coupled with tandem mass spectrometry taking a table and wine grapes as a case study. As expected, the differences between the two cases not only lay in their morphological characteristics, such as size, the shape of the bunches, and thickness of the skin, nor in their cultivation method but also the profile of co-extractives for each case.,When the information of the matrix effect is not taken into account or the correspondence between the matrix selected as the target and the one being analyzed, the consequence is thus being able to In this way, alter changes in the result of quantification of thea pesticide residues either, under or over quantifying it. , when the information of the matrix effect is not taken into account or the correspondence between the matrix selected as the target and the one being analyzed. Different calibration curves with table grapes (muscatel and white) and wine grapes (Chardonnay, Tannat, Merlot, and Albariño) were prepared, and the responses were compared for a representative group of compounds analyzable by GC-MS/MS, which mainly comprised organophosphates, pyrethroids, organochlorines, azoles, and strobilurins. The matrix effect was generally high in most cases, regardless of the type of grape, but the analyte quantification varied from matrix to matrix . In turn, the coextractives profile was evaluated by gas chromatography (Q3-Scan mode) and thin layer chromatography using UV absorption and universal developer to relate the information qualitatively, detecting significant differences in the coextractives profile. Depending on whether they are wine or table grapes, white or red.Agencia Nacional de Investigación e Innovació

Desarrollo de un método multirresiduo para la evaluación en leche cruda de residuos de organofosforados y piretroides aplicados comúnmente en ganadería = Development of a multiresidue method for the evaluation in raw milk of organophosphorus and pyretriods residues commonly applied in livestock production

Dentro de los ectoparasiticidas utilizados en producciones ganaderas, en las que los animales y los procesos industriales generan productos para consumo humano, como la lechería, existen diferentes combinaciones de pesticidas y acaricidas. Si no se administran adecuadamente y no se respetan los compases de espera, se pueden encontrar sus residuos en los alimentos, por ejemplo, en los productos lácteos. Este fenómeno representa un potencial peligro para los consumidores, por lo que es necesario generar herramientas que permitan determinar cómo afectan las diferentes formas de uso en las concentraciones de pesticidas a los alimentos y los intervalos que aseguren su inocuidad al consumirlos. El objetivo de este trabajo fue ajustar y validar una metodología multirresiduo de análisis en leche vacuna cruda para al determinacion de los ectoparasticidas más empleados en ganadería utilizando GC-QqQ-MS, método elegido por su selectividad y especifidad. La preparación de muestra se basó en la metodología oficial para el análisis de residuos de pesticidas en alimentos en los EE.UU: QuEChERS (AOAC International, 2016). Se validó la metodología según el documento SANTE vigente (European Commission. Directorate General for Health and Food Safety, 2015), evaluando veracidad, precisión, linealidad, efecto matriz y límites de cuantificación. Esta metodología es una herramienta útil para determinar curvas de decaimiento de los compuestos aplicados de manera de asegurar a la calidad e inocuidad de la leche vacuna cruda

Desarrollo de un método multirresiduo para la evaluación en leche cruda de residuos de organofosforados y piretroides aplicados comúnmente en ganadería

Among the ectoparasiticides used in livestock production, where animals and industrial processes generate products for human consumption such as dairy products, there are different combinations of pesticides and acaricides. If they are not properly administered and the holding period is not respected, their residues can be present in foods, such as dairy products. This phenomenon represents a potential danger for consumers, so it is necessary to generate tools that allow to determine exactly how different forms of use affect the concentrations of pesticide residues in food and also know the holding period that ensure its innocuity when consumed. The aim of this work was to adjust and validate a methodology of analysis in raw milk for the most used compounds in livestock using GC-QqQ-MS, which is the method of choice for its selectivity and specificity. The sample preparation, was based on the official methodology for the analysis of pesticide residues in food in the US: QuEChERS (AOAC International, 2016). The figures of merit were evaluated according to the SANTE guidelines (European Commission. Directorate General for Health and Food Safety, 2015). This validated methodology is a useful tool to determine the decay curves of the compounds applied in order to assure the food safety.Dentro de los ectoparasiticidas utilizados en producciones ganaderas, en las que los animales y los procesos industriales generan productos para consumo humano, como la lechería, existen diferentes combinaciones de pesticidas y acaricidas. Si no se administran adecuadamente y no se respetan los compases de espera, se pueden encontrar sus residuos en los alimentos, por ejemplo, en los productos lácteos. Este fenómeno representa un potencial peligro para los consumidores, por lo que es necesario generar herramientas que permitan determinar cómo afectan las diferentes formas de uso en las concentraciones de pesticidas a los alimentos y los intervalos que aseguren su inocuidad al consumirlos. El objetivo de este trabajo fue ajustar y validar una metodología multirresiduo de análisis en leche vacuna cruda para al determinacion de los ectoparasticidas más empleados en ganadería utilizando GC-QqQ-MS, método elegido por su selectividad y especifidad. La preparación de muestra se basó en la metodología oficial para el análisis de residuos de pesticidas en alimentos en los EE.UU: QuEChERS (AOAC International, 2016). Se validó la metodología según el documento SANTE vigente (European Commission. Directorate General for Health and Food Safety, 2015), evaluando veracidad, precisión, linealidad, efecto matriz y límites de cuantificación. Esta metodología es una herramienta útil para determinar curvas de decaimiento de los compuestos aplicados de manera de asegurar a la calidad e inocuidad de la leche vacuna cruda