1. Dimethoate detection through a fluorescent coumarin dyeEdoardo Donà, Gerhard J. Mohr, Aleksandra Lobnik, 2024, izvirni znanstveni članek Opis: In this study, we present a straightforward and innovative approach utilizing a coumarin fluorescent dye for the detection of dimethoate in green tea. Initially, the pesticide undergoes hydrolysis in a NaOH solution, yielding our target analyte, methylamine. Following neutralization to pH 9, methylamine reacts with the dye in CH3CN for 20 min. After a careful optimization, we achieved an outstanding linear correlation (R2 = 0.999) for dimethoate, spanning concentrations from 7.8 to 292 µg/L and LOD of 3.2 µg/L. Moreover, we successfully detected dimethoate in green tea, with a recovery of 95.4% (σ = 5.7%). Organophosphates pesticides (OPs), which dimethoate is one of the most used, pose a significant threat due to their toxicity upon both high direct exposure and prolonged low-level exposure, which has been linked to cancer. Therefore, the development of a detection method that is both selective and sensitive is imperative for safeguarding both the population and the environment. This method effectively addresses the stability challenges encountered by enzyme-based fluorescent sensors, thereby opening new avenues for the detection of organophosphate pesticides.
Ključne besede: organophosphate pesticide, methylamine, coumarin, fluorescence detection, dimethoate, TICT, twisted intramolecular charge transfer
Objavljeno v DKUM: 20.12.2024; Ogledov: 0; Prenosov: 3
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2. Preharvest treatments with low-risk plant protection products can help apple growers fulfill the demands of supermarket chains regarding pesticide residues and marketing apples under 0-residue brandsAndrej Paušič, Mihaela Roškarič, Mario Lešnik, 2023, izvirni znanstveni članek Opis: As a result of worried consumer pressure, European supermarket chains (ESC) have developed very strict rules about the number and concentration of pesticide active substance residues (AS) accepted in fruits. So-called fruit quality toxicological burden indicators were developed. If fruit suppliers do not comply with ESC requirements, their fruit is often rejected. It is becoming increasingly difficult for apple producers to meet all the requirements of the ESC, so they need new residue reduction tools. One of the options to lower the concentrations of residue on apples is a preharvest application of low-risk preparations (LRP) based on potassium bicarbonate (KHCO3) = PBC, coconut di-ethanol amide ((CH3(CH2)nC(=O)N(CH2CH2OH)2) = DEA, hydrogen peroxide (H2O2) = HP, and a mixture of microbes (EM) that have the ability to dissolve or disintegrate the AS residue. Trials were carried out to test the concept mentioned above. The application of LRP during the last four weeks of preharvest significantly reduced the residue concentration of pesticide AS in apples. Reduction rates among 25 active substances ranged from 0 to 100%, depending on the combination of LRP and AS. HP had the highest capacity to accelerate AS degradation, PB was the second most efficient, and DEA and EM displayed a low residue disintegration ability. The application of the tested LRP can enable apple growers to produce fruits with significantly lower residue concentrations and allows them to comply more successfully with strict ESC rules based on the calculations of toxicological burden indicators.
Ključne besede: hydrogen peroxide, potassium bicarbonate, effective microbes, detergent, pesticide residues, fruit marketing rules
Objavljeno v DKUM: 19.04.2024; Ogledov: 253; Prenosov: 4
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3. Development of a “0-Pesticide Residue” grape and wine production system for standard disease-susceptible varietiesMihaela Roškarič, Andrej Paušič, Janez Valdhuber, Mario Lešnik, Borut Pulko, 2023, izvirni znanstveni članek Opis: In order to realize the goals of the EU Farm to Fork strategy, grape growers are introducing new grape-growing technologies. Among the new trends, "0-pesticide residue" protection is quite a promising one. Field trials were carried out in vineyards located in the Mediterranean part of Slovenia in 2021 and 2022 to test the "0-pesticide residue" (ZPR) grape protection system with the goal of producing wine without pesticide residues above the limit of 0.001 mg kg(-1). The standard integrated grape protection program (IP) was compared to the ZPR program. The level of infection of leaves and grapes by fungal pathogens did not significantly increase due to the implementation of the ZPR spray program. The amount of yield and quality of yield were not decreased significantly, but a small financial loss of EUR 70-400 ha(-1) appeared at ZPR grape production when compared to the IP production system. The ZPR system enabled a significant decrease in pesticide residue concentration in wine at a rate of 27 applied pesticide active substances in a rage from 20% to 99%. The goal of producing wine without pesticide residues above the limit concentration of 0.001 mg kg(-1) was not completely achieved in these experiments, but we came very close to it with the tested spraying programs. Further finetuning of pesticide positioning and alternative plant protection products in 0-pesticide residue systems is needed.
Ključne besede: grape, wine, pesticide, reduction, economics, IPM, alternative plant protection products
Objavljeno v DKUM: 09.02.2024; Ogledov: 388; Prenosov: 20
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