查找使用阿拉丁产品的科研文献

Uptake kinetics and subcellular distribution of three classes of typical pesticides in rice plants

Jianan Liu,Jinjin Cheng,Chunli Zhou,Liya Ma,Xiaolong Chen,Yong Li,Xing Sun,Xiaolong Yan,Renhua Geng,Qun Wan,Xiangyang Yu

Food safety problems caused by pesticide residues have always been a concern for many people. In this study, we investigated the uptake, translocation and subcellular distribution of neonicotinoid insecticides, triazole fungicides, and sulfonylurea herbicides in rice plants ( Oryza sativa L.). The time-dependent uptake kinetics of the three categories of pesticides with different molecular structures fit a first-order one-compartment kinetic model. The neonicotinoids (log K ow −0.66–0.8) were mainly concentrated in the leaves, and the triazoles (log K ow 3.72–4.4) were mainly concentrated in the roots. Neonicotinoid pesticides in the roots were preferentially transported across the membrane through the symplastic pathway; triazole pesticides except for triadimefon and myclobutanil preferentially passed through the symplastic pathway; and sulfonylurea pesticides (log K ow 0.034–2.89) were first transported upward through the apoplastic pathway. In the roots, neonicotinoids, triazoles, and sulfonylurea herbicides were mainly concentrated in the soluble fractions, cell wall and apoplast fractions, respectively. In addition, there was a high positive correlation between the subcellular distribution of pesticides in the roots, stems and leaves. Molecular weight and log K ow jointly affected the enrichment of triazole pesticides in the roots, stems and leaves and the transfer from stems to leaves, while water solubility and log K ow commonly affected neonicotinoids. There was a correlation between pesticide absorption and the molecular structures of pesticides. To develop pesticides with strong uptake and transport capabilities, it is necessary to consider that the electronegativity of some atoms is stronger, the sum of the topological indices of heteroatoms can be large, and the van der Waals volume increases accordingly.

An alternative analytical strategy based on QuEChERS and dissolvable layered double hydroxide dispersive micro-solid phase extraction for trace determination of sulfonylurea herbicides in wolfberry by LC–MS/MS

Xiaoli Guo,Tingze Ren,Jianchun Ji,Yan Yang,Xin Di

In this work, a combination of QuEChERS and dispersive micro-solid phase extraction (D-μ-SPE) based on dissolvable layered double hydroxide (LDH) has been established for preconcentration and enrichment of sulfonylurea herbicides (SUHs) in wolfberry samples. The QuEChERS was used for extraction and purification of SUHs, followed by D-μ-SPE for further enrichment of targeted analytes to obtain superior extraction performance. Dissolvable LDH nanosheets were used as absorbents, thus eliminating the elution step needed in traditional D-μ-SPE. The main influence experimental variables including pH of sample solution, amount of LDH, vortex time and volume of acidic solution were optimized in detail. Under the optimized conditions, the proposed method shows high precision (RSDs  < 12 .7%), low limits of detection (0.01–0.5 ng/g) and limits of quantitation (0.1–2.0 ng/g), acceptable recovery (80.1%–97.1%), thus making it a good alternative analytical strategy for the determination of SUHs residues at the low nanogram per gram range with desirable sensitivity.

Ionic liquid-based dispersive liquid–liquid microextraction followed by dispersive solid phase extraction coupled with HPLC-DAD for the determination of sulfonylurea herbicides in soymilk samples

Jilong Li,Weili Xu,Xiujuan Wang,Fengze Wu,Lin Wang,Ji Feng,Zhibing Wang,Hanqi Zhang

Enhancing the efficiency of polypyrrole-dodecylbenzene sulfonic acid in-tube solid-phase microextraction coating for analysis of nitrogen-containing pesticides in water environments

Ma Rong,Yu Shuangshuang,Li Yafang,Lin Yan,Ma Xiaodong

Background: With the growing use of nitrogen-containing pesticides in agriculture, their residues in the environment have raised significant public health concerns.Objective: This study aimed to develop a novel PPy-DBSA/IT-SPME coating to enhance the detection efficiency of polar nitrogen-containing pesticides in water matrices.Methods: The preparation conditions were optimized, including pyrrole concentration at 7.0 mol/L, DBSA concentration at 0.014 mol/L, oxidant concentration at 0.35 mol/L, and a coating cycle repeated 10 times. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was employed for detection.Results: The novel coating effectively adsorbed 19 different categories of polar nitrogen-containing pesticides, including sulfonylureas, triazolopyrimidines, diphenyl ether herbicides, benzoylurea insecticides, and phenylurea herbicides, with unadsorbed rates below 10%. The analytical method achieved an average recovery rate of 61.92% to 115.21%, with an RSD below 5.0%. Detection and quantification limits ranged from 0.012 to 0.524 μg/L and 0.127 to 5.243 μg/L, respectively.Conclusion: The developed method is green, efficient, simple, and cost-effective. It offers an environmentally friendly and user-friendly approach for the detection of polar nitrogen-containing pesticide residues, demonstrating good recovery and precision. This method holds potential for wide application in environmental monitoring and food safety.

Colloidal gold-based lateral flow immunoassay for detecting cyclosulfamuron residues in cereal samples

Lu Zeng,Huan Lv,Xiangrui Li,Wenjia Yang,Wencan Luo,Linghong Kong,Qiujin Zhu

Cyclosulfamuron (CS) is a widely used sulfonylurea herbicide in plant cultivation and food production, and poses significant threats to ecological balance and food safety. To address this concern, we designed a novel CS hapten using computer-simulated semi-antigens. A monoclonal antibody (mAb) exhibiting high specificity and affinity was generated, with an affinity constant of 1.049×10 9 L/mol and a semi-inhibitory concentration (IC 50 ) of 4.94 ng/mL. Leveraging this anti-CS mAb, we constructed a rapid, visually detectable, quantitative lateral flow immunoassay (LFIA) to detect CS in cereals. Under the optimal conditions, the cut-off values were determined to be 100 μg/kg for brown rice and corn samples and 50 μg/kg for rice samples. The corresponding limits of detection values (LODs) were found to be 1.93 μg/kg in brown rice, 2.18 μg/kg in corn and 1.93 μg/kg in rice, respectively. The recovery rates ranged from 96.2% to 104.8% with coefficients of variation ranging from 3.5% to 6.4%, showing good agreement with the results obtained by liquid chromatography–tandem mass spectrometry (LC–MS/MS). The proposed assay demonstrated robust analytical performance, with significant application potential for rapid, on-site detection.

Spatiotemporal distribution and potential ecological risks of current-use pesticides (CUPs) in Laizhou Bay, China

Yufei Dai,Xianli Song,Jing Zhao,Limin Wang,Xiaoru Cui,Li Lu,Jingyu Zhang,Haoyu Zhang,Dahai Zhang,Keqiang Li

Pesticides occur widely in coastal waters and potentially pose a risk to marine ecosystems and human health. The spatiotemporal distribution of current-use pesticides (CUPs) was studied in Laizhou Bay (LZB) and the Xiaoqing River watershed in China during the summer of 2022 and spring of 2023. The pesticide composite index ( PCI ) and persistence index ( PI ) were established in association with the risk quotient ( RQ ) to assess the ecological risk in LZB. In this study, 17 and 12 kinds of CUP were detected in rivers and LZB seawater, respectively, with atrazine and neonicotinoid insecticides (NEOs) being the most frequently detected CUPs at higher concentrations. The average concentration of CUPs decreased from rivers to the coast and towards the center of the LZB, with higher levels in spring and lower levels in summer in rivers and a reversed pattern in seawater. The high-risk areas lie in the LZB coastal area and the estuary. Atrazine, chlorpyrifos, and imidacloprid might pose a high risk to aquatic organisms based on the RQ in the LZB, whereas the priority concern pesticides are atrazine and triazophos based on the PCI and PI . This study is of great significance for assessing the composite ecological risk of CUPs in aquatic environments.