农药助剂的安全性评价

简单介绍了农药助剂安全性的研究现状,深入探讨了溶剂、农用表面活性剂以及不同剂型中农药助剂的安全性问题.重点分析了农用表面活性剂对土壤、水体以及生物的危害.从环境安全、农药剂型的改善、农药助剂的管理等角度对农药助剂的发展前景进行展望.综合分析表明:评价农药助剂的安全性有助于了解和分析我国农药的使用现状,对农药的开发及环境管理具有重要的作用,并可为环保等部门提供参考依据.     

ELISA及电化学法检测藠头中氨基甲酸酯类农药残留

建立了克百威ELISA检测技术,配合电化学法对200份出口菖头样品进行氨基甲酸酯类农药残留检测.ELISA法对克百威的最低检测限达10-7g/L,检出10例,检出率5%;电化学法检测,对乙酰胆碱酯酶抑制率超过60%的样品有7例,检出率3.5%.对比分析检测结果得出2种方法检测结果基本吻合.     

Neat法室温合成氯膦酸二辛基酯

磷酰氯类化合物是一类重要的化学中间体,具有十分广泛的用途。传统的合成方法主要是通过二乙基亚磷酸盐与氯代试剂在溶剂中加热来获得短链磷酰氯。本文讨论了在不使用溶剂的前提下,室温合成长链磷酰氯,即Neat法合成氯膦酸二辛基酯。与溶剂法相比,Neat法反应较彻底,产率较高,节约溶剂,绿色环保,具有重要的意义。     

Determination of azinphos-methyl and parathion-methyl in honey by stripping voltammetry

An electrochemical method for the determination of azinphos-methyl and parathion-methyl in honey is presented. The determination is established by adsorptive stripping differential pulse voltammetry at hanging mercury working electrode.In contrast to the chromatographic methods for the determination of pesticide residues, the sample preparation of the proposed method is minimal; analytes were extracted from honey samples with a mixture of (acetone):(Britton-Robinson buffer) and then were analyzed without any additional pretreatment.The response of the analytes either individually or as a mixture was studied for a series of deposition time and molar ratio. Two quantitation protocols were compared, using either the external calibration or the standard addition method. Accuracy was tested with spiked honey samples obtaining good recovery values. The limit of detection for the honey sample (for deposition time of 10 s) was calculated 51.71 μg kg⁻¹ for MeP and 65.87 μg kg⁻¹ for AzMet.     

Experimental and Established Oximes as Pretreatment before Acute Exposure to Azinphos-Methyl

Poisoning with organophosphorus compounds (OPCs) represents an ongoing threat to civilians and rescue personal. We have previously shown that oximes, when administered prophylactically before exposure to the OPC paraoxon, are able to protect from its toxic effects. In the present study, we have assessed to what degree experimental (K-27; K-48; K-53; K-74; K-75) or established oximes (pralidoxime, obidoxime), when given as pretreatment at an equitoxic dosage of 25% of LD₀₁, are able to reduce mortality induced by the OPC azinphos-methyl. Their efficacy was compared with that of pyridostigmine, the only FDA-approved substance for such prophylaxis. Efficacy was quantified in rats by Cox analysis, calculating the relative risk of death (RR), with RR=1 for the reference group given only azinphos-methyl, but no prophylaxis. All tested compounds significantly (p ≤ 0.05) reduced azinphos-methyl-induced mortality. In addition, the efficacy of all tested experimental and established oximes except K-53 was significantly superior to the FDA-approved compound pyridostigmine. Best protection was observed for the oximes K-48 (RR = 0.20), K-27 (RR = 0.23), and obidoxime (RR = 0.21), which were significantly more efficacious than pralidoxime and pyridostigmine. The second-best group of prophylactic compounds consisted of K-74 (RR = 0.26), K-75 (RR = 0.35) and pralidoxime (RR = 0.37), which were significantly more efficacious than pyridostigmine. Pretreatment with K-53 (RR = 0.37) and pyridostigmine (RR = 0.52) was the least efficacious. Our present data, together with previous results on other OPCs, indicate that the experimental oximes K-27 and K-48 are very promising pretreatment compounds. When penetration into the brain is undesirable, obidoxime is the most efficacious prophylactic agent already approved for clinical use.     

改进QuEChERS/超高效液相色谱-串联质谱法同时测定当归中86种农药残留

建立了QuEChERS结合超高效液相色谱-串联质谱(UPLC-MS/MS)法同时测定当归中86种农药残留,比较了9种不同的QuEChERS方法的净化效率和回收率,结果表明,无石墨化碳黑(NGCB)QuEChERS方法效果最佳.在依赖保留时间的多反应监测模式(MRM)下,采用UPLC-MS/MS对农药进行定量.86种农药...     

Trace Identification and Visualization of Multiple Benzimidazole Pesticide Residues on Toona sinensis Leaves Using Terahertz Imaging Combined with Deep Learning

Molecular spectroscopy has been widely used to identify pesticides. The main limitation of this approach is the difficulty of identifying pesticides with similar molecular structures. When these pesticide residues are in trace and mixed states in plants, it poses great challenges for practical identification. This study proposed a state-of-the-art method for the rapid identification of trace (10 mg·L⁻¹) and multiple similar benzimidazole pesticide residues on the surface of Toona sinensis leaves, mainly including benzoyl (BNL), carbendazim (BCM), thiabendazole (TBZ), and their mixtures. The new method combines high-throughput terahertz (THz) imaging technology with a deep learning framework. To further improve the model reliability beyond the THz fingerprint peaks (BNL: 0.70, 1.07, 2.20 THz; BCM: 1.16, 1.35, 2.32 THz; TBZ: 0.92, 1.24, 1.66, 1.95, 2.58 THz), we extracted the absorption spectra in frequencies of 0.2–2.2 THz from images as the input to the deep convolution neural network (DCNN). Compared with fuzzy Sammon clustering and four back-propagation neural network (BPNN) models (TrainCGB, TrainCGF, TrainCGP, and TrainRP), DCNN achieved the highest prediction accuracies of 100%, 94.51%, 96.26%, 94.64%, 98.81%, 94.90%, 96.17%, and 96.99% for the control check group, BNL, BCM, TBZ, BNL + BCM, BNL + TBZ, BCM + TBZ, and BNL + BCM + TBZ, respectively. Taking advantage of THz imaging and DCNN, the image visualization of pesticide distribution and residue types on leaves was realized simultaneously. The results demonstrated that THz imaging and deep learning can be potentially adopted for rapid-sensing detection of trace multi-residues on leaf surfaces, which is of great significance for agriculture and food safety.     

农药沉积利用率喷雾指示剂诱惑红的酶标仪测定方法

诱惑红是一种水溶性染料,近年来被用作农药沉积利用率测定的指示剂.诱惑红的检测方法为高效液相色谱法和分光光度法.高效液相色谱法需要专门的分析仪器,且价格昂贵,可见分光光度计法操作繁琐,试剂用量大,耗时长,均不适宜田间快速高效测定.笔者发展了诱惑红的酶标仪测定方法,简单高效,可批量检测多个样品,且准确度和精密度高,线性关系...     

合成生物学在农残检测领域的应用

近年来,合成生物学在多个领域崭露头角,在农残检测中也发挥着越来越重要的作用。基于合成生物学模块化和工程化指导思想,各种基因部件的多样化组合为农残检测提供更多方案。简便、耐用、低成本、原位检测等特点也使其较传统检测手段具有更强的竞争力。但与此同时,合成生物学在农残检测中的应用也受到复杂检测环境和生物安全性等问题的影响。结合目前合成生物学在有机氯、有机磷、拟除虫菊酯和氨基甲酸酯类农药检测中的应用与创新实例,归纳合成生物学在农残检测中应用的原理,分析并探讨合成生物学技术未来在农残检测中的发展潜力与应用前景。     

Performance comparison of free and immobilised chicken liver esterase inhibited by four different pesticides

BACKGROUND: In enzyme inhibition‐based biosensors for the detection of organophosphate and carbamate pesticides, the biological element is the immobilised esterase which is inhibited selectively by the pesticides. The free chicken liver esterase, which possesses comparable inhibition response to the pesticides as AChE, has been reported. However, the responses to the pesticides are different between the free and immobilised enzyme due to the diffusion limitation. Therefore, in this study four typical pesticides were selected to compare the ability of free and (ion exchange) immobilised chicken enzyme for pesticide detection and reasons for the difference were investigated. RESULTS: For dichlorvos and malathion at a concentration of 0.1 mg L^?1, the inhibition of the immobilised enzyme was 26.98% and 48.72%, respectively, higher than that for the free enzyme, while the percentage inhibition of free and immobilised enzyme differed very little for trichlorfon at 0.1 mg L^?1. In the meantime, carbaryl at a concentration of 2.5 mg L^?1 showed a 17.72% inhibition for immobilised enzyme which was 13.64% higher than that for the free enzyme. The Michaelis constant of immobilised enzyme was lower than that of the free one and suitable pH values for the free and immobilised enzyme were 7.5 and 8.0, respectively. CONCLUSIONS: The sensitivity of chicken liver esterase to the pesticide inhibition could be improved by immobilisation. Smaller K_m and a lower pH for the micro‐environment of immobilised enzyme should result in higher percentage inhibition compared with that of the free enzyme. Copyright © 2008 Society of Chemical Industry