Qingrong Peng

Surface-active ionic liquids (SAILs) are a new class of ILs that can enable green extraction processes. This study examined the extraction effect of nine S

Converting pesticides into ionic liquids by designing counterions can modulate their physicochemical properties, thus improving their efficacy and environmental safety. In this study, eight prochloraz-based ionic liquids (PILs) were synthesized using natural organic acids, and their physicochemical properties, toxicity, antifungal activity, and efficacy in postharvest mango preservation were evaluated. The results showed that the physicochemical properties of propiconazole, including water solubility, logK_ow, surface activity, and light stability, could be adjusted by selecting counterions with varying structures. These properties were correlated with toxicity to zebrafish embryos and antifungal activity against Colletotrichum gloeosporioides. Notably, except for the benzoate PIL, the photostability of the other seven PILs was enhanced under UV irradiation, with the cinnamate PIL exhibiting a half-life 2.28 times longer than prochloraz. Spectral analysis indicated that the anions influenced photostability by shielding or interacting with the cations. Furthermore, the three selected PILs improved pesticide deposition on the mango surface during preservation, and the salicylate PIL enhanced pesticide penetration into the fruit, potentially contributing to its therapeutic activity. In conclusion, the ionic liquid strategy offers an effective method to modify pesticide properties, improve photostability, reduce losses, and optimize pesticide formulation.

随着农药的广泛使用,其已普遍存在于环境中,对人们的身体健康产生巨大影响。因此,环境中农药残留的去除和分析检测对保护人体安全健康至关重要。同时,农药在环境中残留浓度低,需要一种对目标物有较强选择性和富集作用,并对环境影响小的前处理吸附剂。植物源生物炭是由植物源生物质作为碳源衍生得到的材料,其比表面积大、孔容量高、表面官能团可调节,且环境相容性好,其原料植物源生物质的价格低廉、来源广泛并可再生,是一种廉价高效的吸附剂。该文主要综述了近10年来植物源生物炭用于环境中农药残留去除和分析检测前处理的应用进展。其中在农药残留去除方面的应用主要包括降低农药在土壤中的移动性,修复手性农药造成的污染,负载降解农药的细菌及作为化肥的缓释载体。在农药残留分析检测前处理方面,植物源生物炭可用作分散固相萃取、固相微萃取和磁性固相萃取的吸附剂来选择性吸附水果和蔬菜中的有机磷类和三唑类农药,以及水环境中的有机氯类农药。另外,还介绍了植物源生物炭的吸附机理,详细阐述了基于计算模拟如密度泛函理论、分子动力学模拟和巨正则蒙特卡洛模拟的吸附机理研究并讨论了其优势。最后,总结了植物源生物炭在农药去除和农药残留分析检测前处理方面应用的优势,指出了其在农药残留领域应用待解决的问题。

BACKGROUND: Pesticide residues in fruits and vegetables threaten food safety. Cleaning before eating is a usual way to remove pesticide residues, so it is very important to find the most efficient cleaning conditions for public health. However, many previous cleaning studies only focused on a single variable which required a large amount of time manpower and material resources. Plackett–Burman design (PBD) and response surface methodology can avoid the earlier‐mentioned problems and have potential in studying the influence and interaction of multiple factors. In this study, the effect of five factors on the removal of triadimefon and boscalid from rape by ultrasonic washing was evaluated through PBD: pH of water, ultrasonic cleaning time, water temperature, initial residual concentration and volume of water.RESULTS: Temperature had a significant effect on the rate of triadimefon removal while the other four factors impacted boscalid removal greatly. A higher temperature was better for the removal rate of triadimefon. Under alkaline environment, when initial residual concentration and cleaning time increased with decreasing water volume, the removal rate of boscalid increased. Furthermore, the interactions among factors were obtained. The regression coefficients of fitting equations about triadimefon and boscalid were 0.9657 and 0.9738, respectively.CONCLUSION: Changing pH of water, cleaning time, water volume and temperature during the washing process of rape through PBD designed experiments represents a valid strategy for improving the removal rate of two pesticides residue. This study provides a reference for ultrasonic cleaning conditions by a sink dishwasher, which has a positive effect on food safety. © 2021 Society of Chemical Industry.

In this work, quaternary ammonium based ionic liquids (ILs) are proven to be good candidates to act as green solvents/solubilizers for pesticide formulations. The surface activity of six ionic liquids ([M₃C_nN]X; M = CH₃; n = 10, 12, 14; X = Cl, Br) was tested, along with the corresponding critical aggregation concentration (CAC), lowest surface tension (γ_CAC), maximum surface excess concentration (Γ_max), minimum area per molecule (A_min) and higher adsorption efficiency (pC₂₀), which were measured using several methods, including surface tension measurements, electrical conductivity measurements, steady-state fluorescence measurements and ¹H NMR. The thermodynamic parameters of micellization, the viscosities and the activation energies of the six ILs in 30% aqueous solutions, over the temperature range of 288–308 K, were determined and calculated. The results indicated that the solubilities of representative pesticides (metolachlor, acetochlor, clethodim, thiamethoxam, prochloraz, acetamiprid and fosthiazate) in different concentrations of these ILs were significantly higher than in pure water, especially for prochloraz (e.g., 137.2 g L⁻¹ in 30% C10Br, 4035 times higher than in pure water). The microenvironment existing between the pesticide and micelle was investigated using ¹H NMR techniques, revealing that micelle localization of pesticide molecules and a change in micelle conformation occurred in the dissolving process.

Among eight ionic liquids (ILs) examined, 1-n-butyl-4-methyl-pyridinium bromide (BMPyBr, 5) was used in this study as an appropriate alternative to benzene homologs and derivatives to be used in 10 wt% water-insoluble difenoconazole emulsifiable concentrate (EC). Moreover, 10 wt% difenoconazole EC with BMPyBr (5) exhibited the same efficacy as 10 wt% difenoconazole wettable powder (WP) against powdery mildew on cucumbers under field conditions. The results revealed that difenoconazole EC with BMPyBr (5) had excellent stability at 268 K and 327 K after 14 days through high-performance liquid chromatography (HPLC). Therefore, ILs can be considered as promising environment-friendly adjuvants for pesticides that are commercially processed as EC formulation.