Simultaneous determination of strobilurin fungicides residues in bean samples by HPLC-UV-AD using boron-doped diamond electrode

Determination of multi-pesticide residues in agricultural products with a modified QuEChERS process based on magnetic biochar from coconut clothing

In this study, the magnetic biochar material derived from coconut clothing was firstly successfully synthesized by in-situ polymerization method and applied as QuEChERS adsorbents for extracting multi-pesticides. The obtained magnetic coconut-clothing biochar (MCCBC) presented alveolate structure with abundant large irregular pores. The Fe3O4 particles was obviously attached on the surface of biochar. Under the optimized conditions, the modified QuEChERS process based on MCCBC coupled with HPLC-MS/MS for simultaneously extracting and determining 12 pesticides (organophosphorus insecticides and strobilurins) from different agricultural products (tomato, cucumber, cabbage, carrot, peach, pear, grape, apple) was established. After pretreated by MCCBC, most of pesticides had weak matrix effect. This proposed method showed good linearity (2-250 ng g-1) with R2 ≥ 0.9915, and the limits of detection and the limits of quantification were in the range of 0.01-2.67 ng g-1 and 0.03-8.91 ng g-1, respectively. The acceptable recovery was between 71.1 % and 114.0 % with relative standard deviations from 0.31 % to 13.94 %. These results fully demonstrated that the developed method was efficient for simultaneously extracting and determining organophosphorus insecticides and strobilurins in complex agricultural matrix, possessing obvious advantages of higher sensitivity, easier operation and good feasibility. More importantly, this study provided a useful strategy for magnetizing biochar, and the novel biochar from coconut clothing was also introduced as potential adsorbent for other trace organic pollutants.

Determination of strobilurin fungicides residual in vegetables based on amino modified magnetic graphene oxide solid phase extraction coupled with GC-MS/MS

This research investigated the creation and utilization of an amino-functionalized magnetic graphene oxide (Fe₃O₄-NH₂@GO) nanocomposite as a selective sorbent for extracting and identifying strobilurin fungicides (SFs) from vegetable samples. The investigation utilized a method where magnetic solid phase extraction (MSPE) was integrated with Gas chromatography-triple quadrupole mass spectrometer (GC-MS/MS) for analysis. The physicochemical properties of synthesized sorbent were characterized using Scanning electron microscope (SEM) , Fourier infrared transform spectrum (FT-IR) , X Ray Diffraction (XRD), and vibrating sample magnetometry (VSM) techniques. The adsorption performance of Fe₃O₄-NH₂@GO aligned with the pseudo-second-order kinetics, Elovich, and Freundlich isothermal adsorption models, suggesting various interactions with SFs, including π-π interactions, hydrogen bonding, and electrostatic forces. The maximum adsorption capacity of two selected representative SFs (Picoxystrobin and E-metominostrobin) for the adsorbent were 55.85 mg/g and 47.35 mg/g, respectively. Additionally, the amino group exhibited notable potential for SFs adsorption. Parameters for MSPE, such as the quantity of sorbent, adsorption duration, eluent types and volumes, and sample pH, were optimized. Under optimal conditions, the developed method showed satisfactory performance within a range of 10 to 2000 µg L⁻¹ (R² ≥ 0.9969), low detection limits (0.01-0.080 µg/kg), high analyte recovery (80.5-104.3 %), and good precision (RSD ≤ 4.96 %, n = 6). This method is rapid, straightforward, environmentally friendly, demonstrates good sensitivity and providing a new perspectives on developing sorbents for SFs in complex food matrices. Also Fe₃O₄-NH₂@GO as a sorbent firstly used for extraction and enrichment of phenyl fungicides residues in food samples exhibits remarkable promise, thereby contributing to the advancement of pesticides residue determination methodologies.

Uptake, Translocation, and Subcellular Distribution of Strobilurin Fungicides in Cucumber (Cucumis sativa L.)

The absorption, transport, and subcellular distribution of strobilurin fungicides (azoxystrobin, pyraclostrobin, and trifloxystrobin) have been studied in cucumbers. Under hydroponic laboratory conditions, pyraclostrobin and trifloxystrobin mainly accumulated in cucumber roots whereas azoxystrobin accumulated in cucumber leaves. In the subcellular distribution experiment, azoxystrobin mainly accumulated as a soluble component. Pyraclostrobin and trifloxystrobin accumulated more in the organelles and cell walls. Azoxystrobin and pyraclostrobin enter the root primarily through the apoplast pathway, whereas trifloxystrobin enters the root through the symplastic pathway. Azoxystrobin can be transported in cucumber through anion and cation channels, whereas pyraclostrobin and trifloxystrobin can be transported only through anion channels. This study has great significance in evaluating environmental risks and food safety.

Review of the Analytical Methods Based on HPLC-Electrochemical Detection Coupling for the Evaluation of Organic Compounds of Nutritional and Environmental Interest

This review would like to show the state of the art regarding the coupling of High-Performance Liquid Chromatography (HPLC) with Electrochemical Detection (ED). Since a universal detector for HPLC is not available, the electrochemical detection methods, thanks to their versatility and specificity, are competitive with respect to the detectors currently used. The papers present in literature on HPLC-ED technique are analyzed and discussed: for example, they regard the development of analytical determinations of resveratrol, rosmarinic acid, aromatic heterocyclic amines and glyphosate in food matrices such as meat, aromatic plants, vegetables, fruit and tomato juices. These papers show that electrochemical sensors used as detectors for HPLC can offer better sensitivity values than other detectors. Furthermore, the use of specific working potentials allows avoid matrix interferences to be avoided by almost exclusively determining the analytes of interest. It should be underlined that HPLC-ED methods have a selectivity that allows for limitation of the sample preparation and clean-up procedures to a minimum, making them quick and easy to apply. In addition, these methods offer advantages such as the possibility of direct analysis, that derivatization is often not necessary, the cost-effectiveness of the instrumentation and the possibility of regenerating the electrodes which allows numerous analyses in succession.

Extraction and determination of strobilurin fungicides residues in apple samples using ultrasound-assisted dispersive liquid-liquid microextraction based on a novel hydrophobic deep eutectic solvent followed by H.P.L.C-U.V

In this study, several novel and natural hydrophobic deep eutectic solvents (D.E.Ss) were prepared using methyl trioctylammonium chloride (M.T.O.A.C) as H.B.A and different types of straight chain alcohols as H.B.Ds. One of the D.E.Ss composed of M.T.O.A.C and n-butanol was advantageously used to develop an ultrasound-assisted dispersive liquid-liquid microextraction (U.A-D.L.L.M.E) method combined with high-performance liquid chromatography-ultraviolet detection (H.P.L.C-U.V) for the determination of some strobilurin fungicides in apple samples. Several important parameters influencing extraction efficiency were investigated and optimised, including the type and volume of extractant in ultrasound stage, sonication time, the type and volume of D.E.S, sample solution pH and effect of salt addition. Under optimal experimental conditions, the method showed good linearity with correlation coefficients (R²) of 0.9985 - 0.9991 in the linear range of 4-1500 μg kg^-1, low limits of detection of 1.5-2 μg kg^-1 and acceptable extraction recoveries in the range of 76-92%. Enrichment factor was in the range of 95-115. The proposed method was successfully applied for the extraction and preconcentration of trace fungicides in apple samples, and the results demonstrated the potential of the synthesised D.E.S for the extraction and determination of contaminants in aqueous samples.

Emerging nanobiotechnology in agriculture for the management of pesticide residues

Utilization of pesticides is often necessary for meeting commercial requirements for crop quality and yield. However, incessant global pesticide use poses potential risks to human and ecosystem health. This situation increases the urgency of developing nano-biotechnology-assisted pesticide formulations that have high efficacy and low risk of side effects. The risks associated with both conventional and nanopesticides are summarized in this review. Moreover, the management of residual pesticides is still a global challenge. The contamination of soil and water resources with pesticides has adverse impact over agricultural productivity and food security; ultimately posing threats to living organisms. Pesticide residues in the eco-system may be treated via several biological and physicochemical processes, such as microbe-based degradation and advanced oxidation processes. With these issues in mind, we present a review that explores both existing and emerging techniques for management of pesticide residues and environmental risks. These techniques can offer a sustainable solution to revitalize the tarnished water/soil resources. Further, state-of-the-art research approaches to investigate biotechnological alternatives to conventional pesticides are discussed along with future prospects and mitigation techniques are recommended.