Optimization and Validation of HS-GC/MS Method for the Controlled Release Study of Microencapsulated Specific Bioattractants for Target-Plaguicide Production

Insect plagues are a problem often hard to solve due to the harmful effects caused by the pesticides used to combat them. Consequently, the pesticide market is increasingly trying to develop new technologies to prevent the unwanted effects that common plague treatments usually bring with them. In this work, four specific bioattractants of Musca domestica, extracted from fungi (β-ocimene, phenol, p-cresol, and indole) were microencapsulated with β-cyclodextrin in order to produce an economically and environmentally sustainable bait containing biocides in the near future. Cyclodextrins will retain these volatile compounds until their use by the consumer when the product comes into contact with water. Then, the bioattractants will be released in the medium in a controlled manner. An analytical methodology based on headspace extraction coupled to gas chromatography and mass spectrometry (HS-GC/MS) has been developed and validated following Environmental Protection Agency (EPA) and European Commission Directorate General for Health and Food Safety guidelines for the bioattractants controlled release study from the microencapsulated product. The analytical method has been shown to be accurate and precise and has the sensitivity required for controlled release studies of the four bioattractants analyzed. The release of the bioattractants from microencapsulated products achieved the “plateau” after 3 h in all cases.This research was funded by University of the Basque Country (UPV/EHU) (project GIU19/068)

Exploring the Decomposition Products of 1,3,3,3Tetrafluoropropene and Perfluoro-(3-methylbutan-2-one) Gas Mixtures in Medium -Voltage Electrical Switchgear as Alternatives to SF6

In this work, binary and ternary gas mixtures of 1,3,3,3-tetrafluoropropene, HF0234ze(E), and perfluoro-(3-methylbutan-2-one), CF3C(0)CF(CF3)2 with CO, and synthetic air, are presented as alternatives to SF6 in medium-voltage electrical equipment. They were used in four medium voltage switchgear cubicles replacing SF6 gas, and after a period of time, under permanent 30 kV AC voltage, gas mixture samples were extracted and analyzed on the same day using a validated methodology' based on gas chromatography (GC) coupled to mass spectrometry (MS) and thermal conductivity (TCD). CF4 (tetrafluoromethane), C2F6 (hexafluoroethane), C,F6 (hexafluoropropylene), C3FIF7 (1,1,1,2,2,3,3-heptafluoropropane), CHF, (difluoromethane), and the cis and trans-C3H2F4 (1,3,3,3 tetrafluoropropene) have been identified as decomposition products in these gas mixtures. In addition, a quantity of water has been observed, as well as CO in one of the cubicles. The most abundant decomposition products identified in gas mixture samples (C3HF7 and C3F6) together with water and CO content have been quantified using commercial gas mixture reference standards. The toxicity and global warming of the analyzed compounds are evaluated to determine the most adequate gas mixture among those studied as a candidate to substitute SF6.This work was supported the Basque Country Government (project Elkartek KK-2017/00090

Multiple headspace solid-phase microextraction (MHS-SPME) methodology applied to the determination of volatile metabolites of plasticizers in human urine

In the present work, an optimization and validation of an analytical method for the determination of two plasticizer metabolites, 2-ethylhexanol and 4-heptanone in urine, were carried out by multiple headspace solid-phase microextraction (MHS-SPME) coupled to GC-MS. The validation study was successfully performed in terms of stability, method selectivity, linearity, accuracy, recovery, intermediate precision, repeatability, limit of detection (LOD) and limit of quantification (LOQ) in urine samples. Finally, two population group studies were developed in urine samples of volunteers with plastic exposure. First group represents the common plastic exposure of general population and the second one was carried out with healthy moderately trained individuals who have received blood transfusion. This study demonstrates that significantly increased levels of 2-ethylhexanol were found (p < 0.05) in urine samples of volunteers in the early hours after receiving blood transfusion.This work was funded by University of the Basque Country (UPV/EHU) (project GIU19/068) . I. San Román was funded by the University of Basque Country (UPV/EHU)

Grape Polyphenols Supplementation for Exercise-Induced Oxidative Stress

Exercise induces free radicals' overproduction and therefore, an enhancement of oxidative stress, defined as an imbalance between the production of reactive species and the intrinsic antioxidant defense. Redox activity of reactive species plays an important and a positive role on exercise adaptation, but these species at very high concentrations have detrimental effects. As a result, the use of antioxidant supplements for reducing oxidative stress can be an effective health strategy to maintain an optimal antioxidant status. In this sense, grapes are an important source of natural antioxidants due to their high content in polyphenols. They have shown antioxidant potential benefits for the reduction of intense exercise effect in athletes of different sport disciplines. Consequently, it is plausible to hypothesize that a strategic supplementation with grape based products may be a good approach to mitigate the exercise induced oxidative stress. The goal of this review is to present the state of the art of supplementation effects with grape beverages and grape extracts on the oxidative stress markers in athletes. The data of polyphenolic dosages, participant characteristics and exercise protocols are reported

Diffusional Behavior of New Insulating Gas Mixtures as Alternatives to the SF6-Use in Medium Voltage Switchgear

Regarding the use of SF6 in medium voltage switchgear (MVS), a review of alternatives was encouraged by the European Parliament in Regulation No 517/2014. This is aimed at a new regulatory change, that is expected soon, which will include its prohibition, similar to what has happened with other fluorinated greenhouse gases in other fields, like refrigeration. Therefore, there is an urgent need to study the physical and chemical properties of alternative gas mixtures to determine if they are suitable to replace SF6. In this context, this work addresses the difusional analysis of new gases. Binary and ternary mixtures made of 1,3,3,3-tetrafluoropropene (C3F4H2) and heptafluoroisopropyl trifluoromethyl ketone (C5F10O), using dry air as a carrier gas, were studied. The mixtures were analyzed using original equipment, composed of UV-Vis spectroscopy technology in a sealed gas chamber, which is similar to MVS. Consequently, an experimental equipment that monitors the concentration of a gas mixture online and a model that predicts the mixing process were designed and tested. The concentration profiles were obtained concerning both the time and position in the gas chamber, and the diffusional and convectional parameters were numerically calculated and optimized in an algorithm created in Scilab.This research was funded by the Basque Government, grant numbers KK-2017/00090 and KK-2019/00017

HPLC–(Q)-TOF-MS-Based Study of Plasma Metabolic Profile Differences Associated with Age in Pediatric Population Using an Animal Model

[EN] A deep knowledge about the biological development of children is essential for appropriate drug administration and dosage in pediatrics. In this sense, the best approximation to study organ maturation is the analysis of tissue samples, but it requires invasive methods. For this reason, surrogate matrices should be explored. Among them, plasma emerges as a potential alternative since it represents a snapshot of global organ metabolism. In this work, plasma metabolic profiles from piglets of different ages (newborns, infants, and children) obtained by HPLC–(Q)-TOF-MS at positive and negative ionization modes were studied. Improved clustering within groups was achieved using multiblock principal component analysis compared to classical principal component analysis. Furthermore, the separation observed among groups was better resolved by using partial least squares-discriminant analysis, which was validated by bootstrapping and permutation testing. Thanks to univariate analysis, 13 metabolites in positive and 21 in negative ionization modes were found to be significant to discriminate the three groups of piglets. From these features, an acylcarnitine and eight glycerophospholipids were annotated and identified as metabolites of interest. The findings indicate that there is a relevant change with age in lipid metabolism in which lysophosphatidylcholines and lysophoshatidylethanolamines play an important role.This research was funded by UPV/EHU (Project GIU16/04) and the Spanish Ministry of Economy and Competitiveness (Project CTQ2013-46179-R)

Low toxicity deep eutectic solvent-based ferrofluid for the determination of UV filters in environmental waters by stir bar dispersive liquid microextraction.

[EN] In this work, a low toxicity deep eutectic solvent-based ferrofluid is presented for the first time as magnetic fluid to be used as an efficient solvent in liquid-based microextraction techniques. This ferrofluid is made of a hydrophobic deep eutectic solvent, composed by menthol and thymol in a 1:5 molar ratio as carrier solvent, and oleic acid-coated cobalt ferrite (CoFe2O4@oleic acid) magnetic nanoparticles. This material was characterized via magnetism measurement, scanning electron microscopy, infrared spectroscopy and density measurement. The determination of UV filters in environmental water samples was selected as model analytical application to test the extraction performance of this new ferrofluid by employing stir bar dispersive liquid microextraction, prior to liquid chromatography-tandem mass spectrometry analysis. The response surface methodology was used as a multivariate optimization method for extraction step. Under the optimized conditions, good analytical features were obtained, such as low limits of detection between 7 and 83ngL-1, good repeatability (relative standard deviations, RSD (%) below 15%), enrichment factors between 46 and 101 and relative recoveries between 80 and 117%, proving the good extraction capability of this ferrofluid. Finally, the method was successfully applied to three environmental waters (beach and river waters), finding trace amounts of the target UV filters. The presented low toxicity deep eutectic solvent-based ferrofluid results to be a good alternative to conventional solvents used in liquid-phase microextraction techniques.J.L.B. thanks the Generalitat Valenciana and the European Social Fund for his postdoctoral grant, and A.D. thanks the Basque Country Government for her predoctoral contract (Bikaintek 2020 Program from the Regional Minister for Economic Development and Infrastructures (order 2021–1353, file number 021-B2/2020)). Authors also thank to the Magnetism Unit of SGIker of University of Basque Country (UPV/EHU) for kindly carrying out the magnetism measurements. This article is based upon work from the National Thematic Network on Sample Treatment (RED-2018-102522-T) of the Spanish Ministry of Science, Innovation and Universities, and the Sample Preparation Study Group and Network supported by the Division of Analytical Chemistry of the European Chemical Society

Study of Unpicked Grapes Valorization: A Natural Source of Polyphenolic Compounds and Evaluation of Their Antioxidant Capacity

Every year great amounts of high-quality wine grapes are left on the vine unpicked, and consequently lost, to control the overproduction in wine areas with limited appellation production yield. In the context of circular bioeconomy, the valorization of these grapes as a potential source of natural antioxidants is of great interest. The study carried out is focused on the polyphenolic profile characterization of different unpicked grape varieties using the ultrasound-assisted extraction technique to extract the polyphenolic fractions. Moreover, the evaluation of the antioxidant capacity by several assays was carried out: oxygen radical absorbance capacity (ORAC), stability of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), ferric reducing antioxidant capacity (FRAP), cupric reducing antioxidant capacity (CUPRAC) and stability of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS) assays. The results showed a strong relationship between total phenolic content and hydroxycinnamic acids (R2 = 0.9088) followed by flavan-3-ols (R2 = 0.8792) and tannins (R2 = 0.7705). The antioxidant capacity of the grapes was dependent on the total phenolic content. These results supply new information for a better understanding of the importance of giving an added value to the unpicked grapes due to their high content of polyphenols. These findings help the wine sector to consider the valorization of the unpicked grapes, classified as wastes, as an interesting source of natural antioxidants to be used as food supplements and with potential applications in the pharmaceutical industry

Efficacy of Protein Baits with Fipronil to Control Vespa velutina nigrithorax (Lepeletier, 1836) in Apiaries

The yellow-legged hornet (Vespa velutina nigrithorax), outside its natural range, has become a major threat to domestic bees. Several control methods have been used to fight against V. velutina, but the results achieved are not satisfactory. The use of protein baits with biocides has shown to be an effective method to control invasive wasp populations, but they have not been used to control V. velutina. Thus, the efficacy of protein baits containing fipronil to reduce the presence of hornets in apiaries was evaluated in this study. After laboratory determination of the optimal efficacy of a protein bait at a 0.01% concentration of fipronil, field trials were conducted involving 222 beekeepers. The data reported by the 90 beekeepers who completed the requested questionnaire demonstrated that in the groups of apiaries with the highest pressure of hornets (groups with 10–30 and >30 hornets), there was a significant decrease in the presence of V. velutina, lasting at least two weeks. The reduction in the number of hornets was positively correlated with bait consumption, and bait consumption was positively correlated with the number of hornets present at the time of treatment. Although the method used has shown good efficacy and the concentration of fipronil used was very low; possible negative effects on the environment should also be evaluated.This work was funded by the project ATLANTIC POSITIVE (Interreg Atlantic Area EAPA_800/2018), and co-funded by the Department of Economic Development and Infrastructures, and the Department of Education (project IT1673-22) of the Basque Government. Aitor Cevidanes was supported by a ‘Ramón y Cajal’ post-doctoral grant RYC2021-033084-I funded by MCIN/AEI/10.13039/501100011033 and by European Union NextGenerationEU/PRTR. Omaira de la Hera was supported by a pre-doctoral grant funded by Basque Government (project PUE_2021_1_0008)

A novel SPE-UHPLC-DAD method for the determination of fumagillin produced by Aspergillus fumigatus in cell culture media

[EN]Fumagillin is a biomolecule produced by Aspergillus fumigatus that is gaining relevance due to its connection with invasive aspergillosis. The determination of this molecule might help to understand the propagation of this disease and study its use as a potential biomarker. In spite of the interest of fumagillin in microbiological research, no quantitative method has been developed so far for its determination in cell culture media. In this work, the first validated method for the quantitative analysis of fumagillin in RPMI-1640 is presented. The sample treatment consists of a mixed-mode anion exchange Solid Phase Extraction that effectively removes potential interferences and offered a recovery of 83 ± 7%. The analysis was carried out by Ultra High Performance Liquid Chromatography coupled to Diode Array Detection at 336 nm. The method fulfilled the validation criteria established by EMA and FDA guidelines for bioanalysis (selectivity, carry over, linearity, accuracy, precision, dilution integrity and stability) and offers a limit of quantitation (25 μg·L−1) suitable for its intended use. Indeed, the method was satisfactorily applied to the quantification of the fumagillin produced by three strains of Aspergillus fumigatus with different toxin production capacity.This research was funded by University of the Basque Country (UPV/EHU) (project GIU19/068 and project COLAB20/11) and by Basque Government (grant number IT1362-19). XGP was funded by Basque Government