22 research outputs found
La Química Analítica en el espacio Europeo de enseñanza superior : una experiencia piloto en los estudios de Ingeniería Química
Formative and shared assessment as a key aspect in the training of novice university teacher. Field experience in the faculties of science and pharmacy at the University of Granada
Implementing the Use of Collision Cross Section Database for Phycotoxin Screening Analysis
The increased consumption of blue-green algae (BGA)-based dietary supplements has raised concern about their food safety, especially about cyanotoxin presence. The hyphenation of liquid chromatography with ion mobility mass spectrometry represents a relevant tool to screen several compounds in a large variety of food matrices. In this work, ultrahigh-performance liquid chromatography coupled to traveling wave ion mobility spectrometry/quadrupole time-of-flight mass spectrometry (UHPLC-TWIMS-QTOF) was employed to establish the first comprehensive TWIMS-derived collision cross section database (TWCCSN2) for phycotoxins. The database included 20 cyanotoxins and 1 marine toxin. Accurate m/z, retention times, and TWCCSN2 values were obtained for 81 adducts in positive and negative electrospray (ESI+/ESI–) modes. Reproducibility and robustness of the TWCCSN2 measurements were determined to be independent of the matrix. A screening was carried out on 19 commercial BGA dietary supplements of different composition. Cyanotoxins were confidently identified in five samples based on retention time, m/z, and TWCCSN2.The University of
Parma through the action Bando di Ateneo 2021MUR-Italian Ministry of Universities and
Research-D.M. 737/2021-PNR-PNRR−NextGenerationEU,
(ii) from the Project PID2021-127804OB-I00Spanish MCIN/AEI/10.13039/501100011033ERDF A way of making Europe” and from the Andalousian
Government (Project ref. PROYEXCEL_00195)The Grant (FPU17/03810) financed by MCIN/AEI/
10.13039/501100011033, by “ESF Investing in your future”.Grant IJC2019-040989-I funded by
MCIN/AEI/10.13039/501100011033Waters Italy for providing the Atlantis Premier
BEH Z-HILIC colum
Aplicación de la espectrofluorimetría en fase sólida a la determinación de hidrocarburos aromáticos policíclicos en aguas
Se estudian nuevos métodos de análisis de hidrocarburos aromáticos policiclicos (hap) en aguas, mediante espectrofluorimetria en fase sólida (efs) dado su caracter carcinogenico. Se seleccionaron 12 hap y 3 absorbentes (dos hidrofilos y uno hidrofobo) para la fijación y estudio de los analitos. Se consiguen bajos limites de detección y pocas interferencias. A partir del estudio de fijación, longitudes de onda de los máximos de fluorescencia y demás condiciones experimentales se proponen cinco métodos de análisis mediante efs: Determinación de antraceno en aguas, empleando c-18 sílice por espectrofluorimetria convencional. Determinación de benzo(a)pireno fijado sobre sephadex g-25, por fluorescencia sincrónico. Determinación de la mezcla pireno y benzo(a)pireno fijados en sephadex g-25 mediante fluorescencia sincrónica derivada. Determinación simultanea de pireno, benzo(a)antraceno y benzo(a)pireno fijados sobre sephadex g-25 por fluorescencia sincrónica y, finalmente, determinación simultánea de acenafteno, fenantreno y fluoreno, fijados sobre sephadex g-25, mediante espectrofluorimetria sincrónica de ángulo variable. Los métodos propuestos se han aplicado al análisis de aguas de diversa procedencia comprobándose la validez de los métodos propuesto
Determination of Multiclass Cyanotoxins in Blue-Green Algae (BGA) Dietary Supplements Using Hydrophilic Interaction Liquid Chromatography-Tandem Mass Spectrometry
In recent years, the consumption of blue-green algae (BGA) dietary supplements is increasing because of their health benefits. However, cyanobacteria can produce cyanotoxins, which present serious health risks. In this work we propose hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry (HILIC-MS/MS) to determine cyanotoxins in BGA dietary supplements. Target toxins, including microcystin-leucine-arginine (MC-LR) and microcystin-arginine-arginine (MC-RR), nodularin, anatoxin-a and three non-protein amino acids, β-N-methylamino-L-alanine (BMAA), 2,4-diaminobutyric acid (DAB) and N-(2-aminoethyl)glycine (AEG), were separated using a SeQuant ZIC-HILIC column. Cyanotoxin extraction was based on solid–liquid extraction (SLE) followed by a tandem-solid phase extraction (SPE) procedure using Strata-X and mixed-mode cation-exchange (MCX) cartridges. The method was validated for BGA dietary supplements obtaining quantification limits from 60 to 300 µg·kg−1. Nine different commercial supplements were analyzed, and DAB, AEG, and MCs were found in some samples, highlighting the relevance of monitoring these substances as precaution measures for the safe consumption of these products
Una aproximación al proceso análitico. Evaluación formativa en el aprendizaje basado en problemas
Las clases prácticas de laboratorio son esenciales pues permiten al
estudiante afianzar adecuadamente las bases teóricas y conseguir capacidades y
destrezas de tipo práctico difícilmente alcanzables sin ellas.
Estas clases habitualmente se realizan proponiendo a los estudiantes la elaboración de
un experimento siguiendo un procedimiento descrito detalladamente en un guión: la
“receta”. Esta metodología permite que haya estudiantes que realicen “bien” la
práctica correspondiente sin adquirir por ello un aprendizaje significativo sobre lo que
están haciendo.
Por esta razón y partiendo del hecho contrastado de que las investigaciones dirigidas
proporcionan un mejor aprendizaje de los contenidos curriculares de las ciencias
experimentales, se ha optado por la introducción del aprendizaje basado en el
problema (ABP) como propuesta metodológica del proceso de enseñanza-aprendizaje.
Esta modalidad de enseñanza, centrada en el desarrollo de competencias aborda, entre
otras, la resolución de problemas, toma de decisiones, trabajo en equipo,
comunicación, conciencia del propio aprendizaje, pensamiento crítico, y de forma
destacada, las habilidades de coevaluación y autoevaluación.
En esta comunicación se recoge una experiencia llevada a cabo en la parte práctica de
la asignatura Técnicas Instrumentales de Análisis Ambiental, impartida en el primer
curso del Grado en Ciencias Ambientales en el Curso académico 2010-11.SIN FINANCIACIÓNNo data 201
Patrones químicos monocloro, dicloro y tricloro derivados del bisfenol A
Número de solicitud: 200002432Se describe un método para la síntesis y purificación de los derivados monoclorado, diclorado y triclorado de Bisfenol A. El método consiste en la cloración del Bisfenol A y posterior separación de los compuestos mediante cromatografía. Los patrones se identifican de forma unívoca presentando una pureza superior al 99,99 %. La disponibilidad de estos compuestos es de gran interés para los laboratorios de control y análisis químico, fisioquímico y toxicológico con objeto de poder determinar estos compuestos en muestras de interés ambiental, alimentario, cliínico industrial y legal
Multiclass cyanotoxin analysis in reservoir waters: tandem solid-phase extraction followed by zwitterionic hydrophilic interaction liquid chromatography-mass spectrometry
The presence of cyanobacteria and cyanotoxins in all water bodies, including ocean water and fresh water sources, represents a risk for human health as eutrophication and climate change are enhancing their level of proliferation. For risk assessment and studies on occurrence, the development of reliable and sensitive analytical approaches able to cover a wide range of cyanotoxins is essential. This work describes the development of an HILIC-MS/MS multiclass method for the simultaneous analysis of eight cyanotoxins in reservoir water samples belonging to three different classes according to their chemical structure: cyclic peptides (microcystin-LR, microcystin-RR and nodularin), alkaloids (cylindrospermopsin, anatoxin-a) and three non-protein amino acids isomers such as β-methylamino-L-alanine, 2,4-diaminobutyric acid and N-(2-aminoethyl)glycine). A SeQuant ZIC-HILIC column was employed to achieve the chromatographic separation in less than 12 min. Previously, a novel sample treatment based on a tandem solid-phase extraction (SPE) system using mixed cation exchange (MCX) and Strata-X cartridges was investigated with the aim of extracting and preconcentrating this chemically diverse group of cyanotoxins. The Strata-X cartridge, which was configured first in the line of sample flow, retained the low polar compounds and the MCX cartridge, which was at the bottom of the dual system, retained mainly the non-protein amino acids. The optimization procedure highlighted the importance of sample ion content for the recoveries of some analytes such as the isomers β-Nmethylamino-L-alanine and 2-4-diaminobutyric acid. Method validation was carried out in terms of linearity, limit of detection (LOD) and quantification (LOQ), recoveries, matrix effect and precision in terms of repeatability and intermediate precision. This work represents the first analytical method for the simultaneous analysis of these multiclass cyanotoxins in reservoir water samples, achieving LOQs in the very low range of 7·10-3 – 0.1 µg·L-1. Despite high recoveries obtained at the LOQ concentration levels (101.0-70.9%), relative standard deviations lower than 17.5% were achieved.RTI2018-097043-B-I00 financed by MCIN/ AEI /10.13039/501100011033/ FEDER “Una manera de hacer Europa”Spanish Network of Excellence in Sample preparation (RED2018-102522-T)FPU17/0381
Determination of Multiclass Cyanotoxins in Blue-Green Algae (BGA) Dietary Supplements Using Hydrophilic Interaction Liquid Chromatography-Tandem Mass Spectrometry
In recent years, the consumption of blue-green algae (BGA) dietary supplements is increasing because of their health benefits. However, cyanobacteria can produce cyanotoxins, which present serious health risks. In this work we propose hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry (HILIC-MS/MS) to determine cyanotoxins in BGA dietary supplements. Target toxins, including microcystin-leucine-arginine (MC-LR) and microcystin-arginine-arginine (MC-RR), nodularin, anatoxin-a and three non-protein amino acids, beta-N-methylamino-L-alanine (BMAA), 2,4-diaminobutyric acid (DAB) and N-(2-aminoethyl)glycine (AEG), were separated using a SeQuant ZIC-HILIC column. Cyanotoxin extraction was based on solid-liquid extraction (SLE) followed by a tandem-solid phase extraction (SPE) procedure using Strata-X and mixed-mode cation-exchange (MCX) cartridges. The method was validated for BGA dietary supplements obtaining quantification limits from 60 to 300 mu g center dot kg(-1). Nine different commercial supplements were analyzed, and DAB, AEG, and MCs were found in some samples, highlighting the relevance of monitoring these substances as precaution measures for the safe consumption of these products.MCIN/ AEI RTI2018-097043-B-I00Project Junta de Andalucia-Programa Operativo FEDER B-AGR-202-UGR20MCIN/AEI and FSE FPU17/0381