Simultaneous Determination of Pesticides in Fruits by Using Second-Order Fluorescence Data Resolved by Unfolded Partial Least-Squares Coupled to Residual Bilinearization

In the present work, a chemometric-assisted spectrofluorimetric method has been developed for the simultaneous determination of natural fluorescent pesticides, carbaryl, carbendazim, and thiabendazole, in orange and banana. Only a simple extraction with methanol was required as sample pretreatment. Emission-excitation fluorescence matrices were obtained and resolved by using a second-order multivariate calibration method based on unfolded partial least-squares combined with residual bilinearization (U-PLS/RBL) for achieving “second-order advantage.” In this way, pesticides were determined in fruits even in the presence of inner filter effects, background interactions, strong spectral overlapping, and unexpected components. U-PLS can cope with effects that cause trilinearity loss such as, inner filter effects, including background in the calibration set; meanwhile, RBL allows to resolve the presence of unexpected components. The extraction technique was validated against a commonly applied technique based on the use of ethyl acetate and sodium sulfate. Besides, results obtained for real samples were statistically compared with those obtained by using HPLC. LODs of 0.038, 0.054, and 0.018 mg•kg−1 and 0.044, 0.072, and 0.020 mg•kg−1 were obtained for carbaryl, carbendazim, and thiabendazole in banana and orange samples, respectively; values were in accordance with the MRLs (Maximum Residue Limits) established by different official control organizations such as National Food Safety and Quality Service (SENASA), Codex Alimentarius (based on Food and Agriculture Organization (FAO) of the United Nations and World Health Organization (WHO), and Environmental Protection Agency (EPA).National University of Rosario, Faculty of Biochemical and Pharmaceutical Sciences, Rosario, Argentina BIO 253 BIO 415Argentine Catholic University, Faculty of Chemistry and Engineering, Rosario, ArgentinaCONICET (National Centre of Scientific and Technical Research)ANPCyT (National Agency of Scientific and Technological Promotion

Determinación del grado de acidez de vinagres comerciales de distinta materia prima

El objetivo principal de esta investigación es la determinación de la cantidad de ácido acético en diferentes vinagres comerciales mediante una valoración ácido-base para determinar el grado de acidez de los mismos, relacionarlos con las diferentes denominaciones de origen y los distintos tipos de envejecimiento. Así mismo se comprobará que cumplen los límites legales establecidos en relación a acidez y residuo sec

Green electromembrane extraction procedure based on biodegradable chitosan films for determination of polyphenolic compounds in food samples: greenness assessment of the sample preparation approach

A simple, rapid and environmentally friendly method for the electromembrane extraction of polyphenolic compounds has been developed using chitosan films (60% (w/w) chitosan, 40% (w/w)-Aliquat®336, 10–11 μm thickness) as biopolymeric membrane. In this work for the first time with this type of chitosan-based support, the use of organic solvents has been completely eliminated, which allows considering the proposed methodology as a green solvent-free procedure, as demonstrated by performing analytical greenness metric for sample preparation (AGREEprep). Under optimal experimental conditions (10 mL donor phase, pH 7; 50 μL acceptor phase, pH 9; 100 V applied voltage for 15 min) high enrichment factors (EF ≥ 60) were obtained for all the target analytes. Wide concentration ranges between 52.8 μg L− 1 and 1000 μg L− 1 , good linearity (R2 ≥ 0.996), low limit of detection (15.9–37.1 μg L− 1 ), and repeatability (relative standard deviation (RSD) values 4–10%) were achieved. Polyphenolic compounds have been successfully extracted from coffee- and tea-based dietary food supplements in different formats (pills and ampoules). For comparison purposes, target analytes have additionally been determined in green coffee beans and tea.Ministerio de Ciencia e Innovación de España (MCIN) - PGC 2018- 096608-B-C2

Determinación de hidroximetilfurfural en mieles como parámetro indicador de la calidad de las mismas

El objetivo principal de esta investigación es la determinación de la cantidad de hidroximetilfurfural (HMF) en diferentes mieles comerciales mediante el método espectrofotométrico para verificar si pueden ser comercializadas. Además las mieles serán analizadas con el objetivo de determinar la concentración de hidroximetilfurfural después de haber sido expuestas al aire durante diferentes periodos de tiempos y calentadas a distintas temperaturas

Chitosan biofilms: Insights for the selective electromembrane extraction of fluoroquinolones from biological samples

A selective electromembrane extraction procedure for the extraction of Enrofloxacin, Marbofloxacin and Flumequine, usually employed as antibiotic in veterinarian use, is proposed by using a chitosan biofilm, composed by 60% (w/w) chitosan and 40% (w/w) Aliquat®336, as active biopolymeric support. The interaction mechanism occurring between the target drugs and the biopolymer has been deeply studied using the Quantum Theory of Atoms in Molecules. The obtained results show the interaction between the extracted fluoroquinolones and the biomembrane is stabilized by two hydrogen bonds formed between both the carboxyl and keto groups of the drugs with both the amine and hydroxyl groups of glucosamine in the biopolymer. The energetic results agree with the high extraction efficiency obtained for Marbofloxacin, Enrofloxacin and Flumequine in terms of enrichment factors (83, 82 and 58, respectively) in presence of other fluoroquinolones. Under optimum conditions, the proposed electromembrane extraction method exhibits wide linear ranges of 4.2e200 mg L1 , 5.6e200 mg L1 and 5.1e200 mg L1 , respectively; low limits of detection close to 1.3 mg L1 and appropriate repeatability (relative standard deviation values 4e7%).Fondos Europeos FEDER, Ministerio de Ciencia e Innovación y Agencia Estatal de Investigación, de España - PGC2018-096608- B-C22Ministerio de Ciencia, Innovación y Universidades de España - RED2018-102522-TJunta de Andalucía - 2019/FQM-106Premio Mensual Publicación Científica Destacada de la US. Facultad de Químic

Effect of Aliquat®336 on supported liquid membrane on electromembrane extraction of non-steroidal anti-inflammatory drugs

Up to now, most electromembrane extraction methods describe the use of pure organic solvents or mixtures as supported liquid membrane. However, the need to incorporate carriers in the supported liquid membrane to achieve the extraction of high polar compounds, seems to indicate that the presence of certain additives in the organic solvent may improve the extraction yield. For this reason, some studies have tried to enhance electrokinetic migration in different ways, modifying either the supported liquid membrane or even the donor solution. In this work, it has been studied and optimized an electromembrane extraction of five widely used non-steroidal anti-inflammatory drugs: salicylic acid, ketoprofen, naproxen, diclofenac and ibuprofen. The thickness and porosity of the support, the supported liquid membrane composition, the donor and acceptor phase pH, the voltage, the extraction time and the electrode configuration were optimized. supported liquid membrane was modified by adding different amounts of Aliquat®336, a cationic carrier commonly used in electromembrane extraction procedure for anionic compounds. The results compared with those obtained in the same extraction conditions using the pure organic solvent as supported liquid membrane, showed better extraction recoveries. The highest recoveries were achieved using a pH 5 donor phase and an acceptor phase at pH 12. The recoveries were within the range of 39 and 53% after 12 min extraction, using a voltage of 80 V, a stirring speed of 400 rpm and 1-nonanol modified with Aliquat®336 2.5% (w/v) as support liquid membrane. Detection and quantitation limits were within 0.02–1.0 ng mL−1 and 0.05–3.0 ng mL−1, respectively. The selected analytes were extracted by electromembrane extraction using a home-made device designed with a flat configuration. The analyses were carried out by high performance liquid chromatography with diode array and fluorescence detection and finally, applied to the analysis of human urine samples.Ministerio de Educación y Ciencia (MEC). España CTM2015-67902-C-1-

Urine and saliva biomonitoring by HF-LPME-LC/MS to assess dinitrophenols exposure

In this work, the determination of 2,4-, 2,5- and 2,6-dinitrophenols and the identification of some of their metabolites in human urine and saliva is proposed. A three phase hollow fiber based liquid phase microextraction prior to ultra-high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry allowed low detection and quantitation limits of the target analytes, as well as the investigation and tentatively identification of some metabolites by accurate mass full-spectrum measurements. The chromatographic separation was accomplished on an Acquity BEH C18 column (50 mm × 2.1 mm i.d., 1.7 μm particle size) at 25 ºC using water and acetonitrile (with 0.1 % (v/v) formic acid) 20:80 v/v as mobile phase, at a flow rate of 0.5 mL/min in isocratic elution mode for 5 min. Hollow fiber liquid phase microextraction was achieved at donor phase pH 2, acceptor phase pH 13 and dihexylether as supported liquid membrane. Under the optimal conditions, detection limits for 2,4-, 2,5- and 2,6-dinitrophenol, respectively, were 0.18 μg·L-1, 0.38 μg·L-1 and 0.14 μg·L-1 in urine samples and 0.32 μg·L-1, 0.67 μg·L-1 and 0.24 μg·L-1 in saliva samples. The proposed methodology was applied on urine and saliva samples from laboratory staff likely to be or not occupationally exposed to dinitrophenols, finding quantitative levels of 2,4- and 2,6-dinitrophenol and identifying some metabolites previously reported in literature.Ministerio de Economía y Competitividad (MINECO). España CTM2015-67902-C-1-PMinisterio de Ciencia e Innovación (MICIN). España GC2018-096608-B-C22European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER) GC2018-096608-B-C2

Desarrollo de líneas experimentales para su aplicación en los Trabajos de Fin de Grado en Química

Desde el punto de vista académico, los Trabajos Fin de Grado en Ciencias Químicas se presentan como proyectos experimentales relacionados con problemas reales, orientados a progresar en conocimientos y fortalecer competencias adquiridas, convirtiéndose en claves del currículo para el mundo profesional. Se abordan una serie de proyectos de laboratorio como una aproximación más realista al aprendizaje integral. La metodología docente propuesta favorece la búsqueda de información, pensamiento crítico, superación continua y éxito de los estudiantes, similar a la que se realiza en el mundo real, estimulando su interés y motivación durante el proceso de aprendizaje.Des del punt de vista acadèmic, els Treballs Fi de Grau en Ciències Químiques es presenten com a projectes experimentals relacionats amb problemes reals, orientats a progressar en coneixements i enfortir competències adquirides, convertint-se en claus del currículum per al món professional. S'aborden una sèrie de projectes integrals de laboratori com una aproximació més realista a l'aprenentatge integral. La metodologia docent proposta afavoreix la busca d'informació, pensament crític, superació contínua i èxit dels estudiants, semblant a la què es realitza en el món real, estimulant el seu interès i motivació durant el procés d'aprenentatge.From the academic point of view, the bachelor thesis in Chemistry is presented as a project based on a real problem. The goal is to progress in strengthening knowledge and skills already acquired. This is a key element for the students curricula related to their integration into the professional world. A comprehensive series of laboratory projects have been developed as a more realistic approach to the concept of integral learning. Teaching methodology promotes information searching, critical thinking, continuous improvement and success. The procedure is performed in conditions close to the real world, stimulating interest and motivation during the learning process

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality