戊唑醇在葡萄和土壤中的残留和消解动态

建立了葡萄中戊唑醇残留的气相色谱测定方法,并研究了其在葡萄和土壤中的消解动态。土壤用乙腈提取,无需净化,葡萄样品用甲醇提取,二氯甲烷液液分配净化后用气相色谱-氮磷检测器(GC-NPD)测定。结果表明:在 0.01、0.1、1 mg/kg 3个添加水平下,戊唑醇的平均回收率为85.0%~98.8%,相对标准偏差(RSD)为2.9%~10.4%;最小检出量为1×10-11g,最低检测浓度为0.01 mg/kg。采用250 g/L戊唑醇水乳剂按有效成分187.5 mg/L剂量(推荐剂量的1.5倍)施药,戊唑醇在葡萄中的半衰期为9.8~12.2 d,在土壤中的半衰期为8.2~17.3 d,药后28、35 d葡萄中的最终残留量≤0.81 mg/kg,低于国际食品法典委员会(CAC)和中国规定的最大残留限量2.0 mg/kg。建议在葡萄上使用250 g/L戊唑醇水乳剂时,施药剂量最高为有效成分187.5 mg/L,施药2~3次,采收间隔期为28 d。     

不同清洗和储藏方式下戊唑醇在黄瓜中的残留变化

以田间施药后的黄瓜为研究对象,模拟家庭清洗和储藏方式,利用液相色谱串联三重四级杆质谱(ultra performance liquid chromatography coupled with tandem mass spectrometry,UPLC-MS/MS)对不同清洗和储藏方式下黄瓜中的戊唑醇残留进行测定,旨在探究从田间到餐桌,鲜食黄瓜时农药残留的去除方法,为膳食风险评估提供理论参考。结果表明,在不同的清洗方式下清洗15 min后,黄瓜中戊唑醇的去除率达到31.82%~78.79%。其中5%乙酸溶液对戊唑醇去除效果最佳。室温22℃时放置48h戊唑醇去除率达到67.42%。超声波清洗15min后戊唑醇的去除率为76.51%。     

戊唑醇分子印迹传感器制备及其农药残留检测的电学传感机理分析

以甲基丙烯酸为功能单体,戊唑醇(tebuconazole,TEB)为模板分子,乙二醇二甲基丙烯酸酯为交联剂,应用电化学聚合法制备了分子印迹电化学传感器(TEB-MIP/F-CNTs/GCE)。利用循环伏安法(cyclic voltammetry,CV)和交流阻抗法(electrochemical impedance spectroscopy,EIS)对新型传感器进行了表征,并用差分脉冲伏安法(differential pulse voltammetry,DPV)考察了新型传感器对戊唑醇的检测性能。结果表明:戊唑醇分子印迹电化学传感器具有一定特异性;传感器表观表面积比裸电极显著提高;新型传感器具有良好的印迹效果,相较于其他结构类似的三唑类化合物(如苯醚甲环唑),TEB-MIP/F-CNTs/GCE对戊唑醇表现出高效的识别能力,具有专一性和强选择性,且在C_(TEB)≤2.0×10~(-6)mol/L范围内传感器峰电流与C_(TEB)存在定量关系;数据模拟分析得到传感器的电学阻抗谱等效电路模型为R_1(CPE_1(R_2(CPE_2(R_3)))),计算各电极/传感器的等效电路中各元件参数,证明该模型能有效地模拟传感器检测戊唑醇的传感机理。该研究结果可为三唑类农药残留仿生免疫检测方法的建立提供技术支撑。     

Laboratory studies on formation of bound residues and degradation of propiconazole in soils

Laboratory studies on the formation of bound residues and on the degradation of the triazole fungicide propiconazole were conducted in two different soils. Soils treated with 14C-propiconazole were incubated at 22 degrees C and extracted exhaustively with a solvent at each sampling date until no further propiconazole was extracted. The solvent-extractable residues were used to measure propiconazole remaining in the soil, and the extracted soils were used to investigate bound residues of propiconazole. Mineralization of propiconazole was investigated by measuring [14C]carbon dioxide evolved from the soil samples. Formation of bound residues of propiconazole was higher in silty clay loam soil than in sandy loam soil, giving approximately 38 and 23% of the applied 14C, respectively. In contrast, the rates of degradation and mineralization of propiconazole were lower in silty clay loam soil than in sandy loam soil. Decreased extractability of the 14C residues with incubation time was observed with increased formation of bound residues. When the propiconazole remaining in the solvent-extractable residues was quantitatively measured by high-pressure liquid chromatographic analysis, the half-life value in sandy loam soil was about 315 days, while the half-life in silty clay loam soil exceeded the duration of the 1 year experimental period. Increased formation of bound residues was observed as propiconazole degraded with incubation time, suggesting that degradation products are involved in the formation of bound residues. Our study suggests that the formation of bound residues of propiconazole contributes to the persistence of this fungicide in soil.     

6%戊唑醇微乳剂

本文介绍了6％戊唑醇微乳剂配方的组成和制备方法，并对其性能和田间药效进行了测试和试验。     

长期施药果园中的苹果轮纹病菌对戊唑醇和甲基硫菌灵的敏感性

为了监测果园中苹果轮纹病菌对戊唑醇和甲基硫菌灵敏感水平的变化,采用菌丝生长速率法测定了采集自山东烟台地区和北京市昌平区,有较长施药史苹果园中的苹果轮纹病菌对戊唑醇和甲基硫菌灵的敏感性。结果表明:戊唑醇对连续施用戊唑醇5年、每年施药1~2次的果园中苹果轮纹病菌的EC_(50)为0.017 4~0.114 3μg/mL,即该类果园中苹果轮纹病菌对此药的敏感性仍然保持在较高水平,与野生菌株的敏感性非常接近,没有出现敏感性分化的抗药亚群体;甲基硫菌灵对连续施用甲基硫菌灵10年、每年施药2次的果园中苹果轮纹病菌的EC_(50)为0.846 4~4.677 4μg/mL,果园中苹果轮纹病菌与野生菌株相比EC_(50)平均值约上升3.15倍,最低值和最高值分别是已报道敏感性基线的1.19倍和6.59倍,没有出现敏感性发生显著分化的抗药性亚群体。     

负载戊唑醇的壳聚糖纳米胶囊的制备与性能研究

以戊唑醇为囊芯,壳聚糖和甲基丙烯酸甲酯为囊壁,采用自组装的方法制备了壳聚糖戊唑醇纳米胶囊。采用动态光散射仪(DLS)和透射电镜(TEM)对其粒径和形貌进行了表征,纳米胶囊的平均粒径(D50)为220 nm,分布系数(PDI)为0.23;经高效液相色谱仪测定,纳米胶囊的载药量为21.8%,包覆率为85.7%,体外释放192 h的释药率为65.97%。用带毒培养基法测试了其对3种木竹材霉菌的抑制性能。结果表明,与相同质量浓度(48.2 mg/L)的戊唑醇乙酸乙酯溶液相比,载戊唑醇纳米胶囊处理前20 d抑菌效果较低,但随着时间的延长仍能保持较高的抑菌活性,药剂处理40 d时对木霉、青霉、黑曲霉菌的抑菌率分别仍达70.6%、66.4%和89.1%。研究结果可为纳米胶囊木竹材防霉剂的开发奠定基础。     

马铃薯中戊唑醇和吡唑醚菌酯的残留行为

为探明戊唑醇和吡唑醚菌酯在马铃薯中的残留特性和安全性,建立了测定马铃薯植株和块茎中戊唑醇和吡唑醚菌酯残留量的分析方法,研究了两种农药在马铃薯植株中的消解动态及在马铃薯块茎中的最终残留。样品前处理采用 QuEChERS 法,经乙腈提取,高效液相色谱-串联质谱检测,外标法定量。结果表明:0.005～0.5 mg/kg添加水平下,戊唑醇在马铃薯植株和块茎中的回收率分别为90%～99%、94%～102%,相对标准偏差(RSD)分别为3.8%～5.3%、5.3%～9.2%;吡唑醚菌酯在马铃薯植株和块茎中的回收率分别为98%～104%、89%～96%,相对标准偏差(RSD)分别为4.0%～8.7%、3.0%～8.0%;样品中戊唑醇和吡唑醚菌酯的定量限(LOQ)均为0.005 mg/kg。监测了戊唑醇和吡唑醚菌酯在山东烟台、天津武清、四川成都、重庆九龙坡、湖南长沙、安徽宿州、陕西榆林、贵州贵阳、宁夏银川和黑龙江绥化10个试验点的马铃薯中的残留行为。发现戊唑醇和吡唑醚菌酯在马铃薯植株中的消解速率较快,半衰期分别为6.4～6.5 d和5.0～7.2 d,属易消解型农药。采用32%戊唑醇·吡唑醚菌酯悬浮剂按推荐剂量(有效成分用量182.4 g/hm2)施药3次,距末次施药14 d,戊唑醇在马铃薯中的最大残留量不大于0.018 mg/kg,低于欧盟规定的最大残留限量标准(MRL)(0.02 mg/kg),吡唑醚菌酯在马铃薯块茎中的最大残留量<0.005 mg/kg,低于中国规定的MRL(0.02 mg/kg)。     

戊唑醇防治小麦赤霉病施药时期及安全性评价

为了明确戊唑醇防治小麦赤霉病的关键施药时期及其安全性,进行了戊唑醇防治小麦赤霉病施用浓度和时期的田间试验。结果表明,25%戊唑醇EC在有效成分150g/hm2和75g/hm2两个施用剂量下对小麦赤霉病的防治效果没有显著差异,对病穗率和病情指数的防治效果分别为83.7%、86.0%和85.1%、88.5%;25%戊唑醇EC在有效成分150g/hm2施用剂量下在齐穗期到灌浆初期喷施对小麦安全,以盛花期施药对小麦赤霉病的防治效果最好,对病穗率和病情指数的防治效果分别为80.6%和84.1%,其次为齐穗期和初花期施药,对病穗率和病情指数的防治效果分别为53.9%、53.3%和54.6%、56.8%,灌浆初期施药的防治效果最差。     

Behaviour of trifloxystrobin and tebuconazole on grapes under semi‐arid tropical climatic conditions

BACKGROUND: A mixture of trifloxystrobin and tebuconazole is excellent in controlling both powdery and downy mildew of grapes. The objective of the present work was to study the behaviour of trifloxystrobin and tebuconazole on grape berries and soil following treatment with Nativo 75 WG, a formulation containing both fungicides (trifloxystrobin 250 + tebuconazole 500 g kg^?1). This study was carried out for planned registration of this mixture for use on grapes in India. RESULTS: Initial residue deposits of trifloxystrobin and tebuconazole on grapes were below their maximum residue limit (MRL) of 0.5 and 2 mg kg^?1, respectively, when Nativo 75 WG was applied at the recommended dose of 175 g product ha^?1. The residues dissipated gradually to 0.02 and 0.05 mg kg^?1 by 30 days, and were below the quantifiable limit of 0.01 mg kg^?1 at the time of harvest (60 days after the last treatment). Trifloxystrobin and tebuconazole dissipated at a pre‐harvest interval (PHI) of 36 and 34 days, respectively, from the recommended treatment dose. The acid metabolite of trifloxystrobin, CGA 321 113, was not detected in grape berries at any point in time. Soil at harvest was free of any pesticide residues. CONCLUSION: Residue levels of both trifloxystrobin and tebuconazole were below MRLs when grapes were harvested 30 days after the last of four applications of 175 g product ha^?1 (trifloxystrobin 44 g AI ha^?1, tebuconazole 88 g AI ha^?1) under the semi‐arid tropical climatic conditions of India. Copyright © 2010 Society of Chemical Industry     

氯啶菌酯与戊唑醇混合物对水稻稻瘟病菌的联合毒力及防效

为了明确氯啶菌酯与戊唑醇混合物对水稻稻瘟菌(Magnaporthe oryzae)的毒力增效作用, 采用菌丝生长速率法测定了氯啶菌酯、戊唑醇及其不同比例混合物对水稻稻瘟菌的毒力, 并通过田间试验评价了其对水稻稻瘟病的防治效果和水稻安全性的影响。结果表明:氯啶菌酯与戊唑醇质量比为8∶1的混合物对抑制菌丝生长增效最为明显, 增效系数为2.71。在田间药效试验中, 15%氯啶菌酯?戊唑醇悬浮剂150 g/hm2对水稻稻瘟病的防效为81.54%, 高于常规药剂三环唑, 且对水稻整个生育期生长安全。     

2013年湖北省小麦赤霉病菌对多菌灵和戊唑醇的敏感性

2013年从湖北省7个小麦主产区分离获得106株禾谷镰刀菌,测定了其对戊唑醇和多菌灵的敏感性。结果表明:戊唑醇和多菌灵对所有供试菌株的EC50值分别为0.064~0.778和0.090~0.858 mg/L。采用SAS软件的W法对EC50分布进行了正态性检验,表明106株菌株对戊唑醇和多菌灵敏感性的频率分布符合正态分布,其EC50平均值分别为(0.383±0.129)和(0.526±0.151)mg/L。不同地区来源的菌株对两种药剂的敏感性存在显著差异,其中襄阳的菌株对两种药剂的敏感性显著低于其他6个地区的。研究结果显示:湖北省小麦赤霉病菌未出现对戊唑醇和多菌灵抗性菌群,两种药剂用于防治小麦赤霉病仍具有使用价值。     

河北省梨树褐斑病菌对不同机制杀菌剂的敏感性及其与戊唑醇敏感性的关系

为明确河北省梨树褐斑病菌(Septoria piricola Desm)对戊唑醇和双胍三辛烷基苯磺酸盐、吡唑醚菌酯、环丙唑醇等不同作用机制杀菌剂的敏感性及交互抗性,采用室内菌丝生长速率法和田间小区试验分别测定了不同杀菌剂对11个地市分离到的133株病菌菌株的毒力,以及对梨树褐斑病的防治效果,研究了病菌对戊唑醇与对双胍三...     

中国河南省小麦纹枯病菌对苯醚甲环唑及戊唑醇的敏感性

为明确中国河南省小麦纹枯病菌对苯醚甲环唑及戊唑醇的敏感性,采用菌丝生长速率法测定了2种药剂对采自河南省15个地市分离的95株病菌的毒力。结果显示:供试菌株对苯醚甲环唑和戊唑醇的EC50值分别在0.014~1.609和0.002~0.064 μg/mL之间。敏感性频率分布图显示:在小麦纹枯病菌群体中已出现对苯醚甲环唑敏感性下降的亚群体,而对戊唑醇则不明显;可将其中呈连续单峰频次分布的大多数菌株群体的平均EC50值（0.165±0.101）和（0.019±0.008）μg/mL分别作为小麦纹枯病菌对苯醚甲环唑和戊唑醇的相对敏感基线。苯醚甲环唑的平均EC50值是戊唑醇的26倍,表明该病原菌对戊唑醇更为敏感。不同地区病原菌群体间对苯醚甲环唑和戊唑醇的敏感性均存在显著性差异。小麦纹枯病菌对2种杀菌剂的敏感性之间存在着微弱的正相关性。本研究结果可为河南省小麦纹枯病防控杀菌剂的合理使用提供理论依据。     

聚羧酸盐和聚氧乙烯醚磷酸酯分散剂复配体系对戊唑醇水悬浮剂分散稳定性的影响

聚羧酸盐和聚氧乙烯醚磷酸酯分散剂复配体系有利于提高农药水悬浮剂的物理稳定性。本研究选用430 g/L戊唑醇水悬浮剂 (SC) 作为研究对象,研究了聚羧酸盐分散剂850和聚氧乙烯醚磷酸酯分散剂601p复配体系的胶束流体动力学直径以及对戊唑醇SC黏度、Zeta电势、比吸光度和流变性质的影响。结果显示:单独用601p制备的戊唑醇SC的分散稳定性要高于单独用850制备的,而用两者复配体系制备的戊唑醇SC的稳定性明显高于用单一分散剂制备的。进一步研究发现,分散剂的复配比例对戊唑醇SC的物理稳定性也有不同影响,其中当m(850) : m(601p) = 1 : 1时,复配分散剂的胶束动力学直径不再变化,制得的戊唑醇SC分散稳定性最好,表现为黏度相对较小,Zeta电势为 –40.8 mV。     

Effects of tebuconazole on morphology,structure, cell wall components and trichothecene production of Fusarium culmorum in vitro

The effects of tebuconazole, a systemic fungicide, on the morphology, structure, cell wall components and toxin production of Fusarium culmorum were investigated in vitro. Treatment was by application of four filter paper strips (0.75 cm × 5.0 cm) soaked in 20 µg ml ^?1 fungicide placed around a point inoculum in Petri dishes. Mycelial growth was strongly inhibited by fungicide treatment. Scanning electron microscopic observations showed that the fungicide caused irregular swelling and excessive branching of hyphae. The morphological changes induced by the fungicide at the ultrastructural level included considerable thickening of the hyphal cell walls, excessive septation, the formation of the incomplete septa, extensive vacuolisation, accumulation of lipid bodies and progressing necrosis or degeneration of the hyphal cytoplasm. Non‐membrane inclusion bodies were often detected in the hyphal cytoplasm. Furthermore, the formation of new hyphae (daughter hyphae) inside collapsed hyphal cells was common following treatment. The daughter hyphae also displayed severe alterations such as irregular thickening of the cell walls and necrosis of the cytoplasm. Using cytochemical techniques, the labelling densities of chitin and β‐1,3‐glucan in the cell walls of the fungicide‐treated hyphae were more pronounced than in those of the control hyphae. Moreover, immunogold labelling with antiserum against deoxynivalenol (DON) revealed that Fusarium toxin DON was localized in the cell walls, cytoplasm, mitochondria and vacuoles of the hyphae from the control and the fungicide treatment, but the labelling density in the fungicide‐treated hyphae decreased dramatically compared with the control hyphae, indicating that tebuconazole reduced Fusarium toxin production of the fungus. © 2001 Society of Chemical Industry     

多菌灵/戊唑醇复配对小麦赤霉病菌抗药性菌株的活性增效作用

为了解决小麦赤霉病菌抗药性以及明确杀菌剂复配增效作用,采用菌丝生长速率法、孢子萌发法、渗透压测定、甾醇含量测定等方法研究了多菌灵与戊唑醇复配对赤霉病菌抗药性菌株Nj-1-1的活性增效作用。研究表明:复配药剂虽不能完全抑制孢子萌发及菌丝生长,但可以减慢孢子萌发速率,同时破坏抗性菌株细胞膜的渗透性及内含物,从而初步解释多菌灵与戊唑醇复配组合的增效原因。