双甲脒分析方法的国际协作研究

结合参加双甲脒分析方法的国际协作研究，对国际分析方法协作研究的一般程序做了介绍，反映了国际同行们的分析水平。对国内同行了解和掌握国际协作研究的程序，及国内分析方法标准的协作实验验证也有所裨益。     

双甲脒与氰戊菊酯或氯氰菊酯混用对烟蚜的药效

用浸渍法测定了双甲脒与氰戊菊酯或氯氰菊酯混用对烟蚜Myzuspersicae(Sulzer)的毒力。结果表明 ,当双甲脒与氰戊菊酯以 1∶2、1∶5和 2∶1的比例混用时表现为药效增效作用 ,其中以 1∶2配比共毒系数最大。当双甲脒与氯氰菊酯以 1∶1、1∶2、2∶1和 5∶1的比例混用时表现为药效增效作用 ,其中以 1∶1配比共毒系数最大。并对双甲脒与拟除虫菊酯类杀虫剂混用防治蚜虫的配比进行了讨论     

Development and validation of an analytical method for total amitraz in fruit and honey with quantification by gas chromatography-mass spectrometry

The EU maximum residue limit (MRL) definition for amitraz is 'the sum of amitraz plus all its metabolites containing the 2,4-aniline moiety, expressed as amitraz'. A rapid and sensitive method has been developed and validated in-house for the determination of total amitraz in pears, strawberries, oranges and honey. Samples were hydrolysed (under acidic followed by alkaline conditions) to convert amitraz to 2,4-dimethyaniline, which was then partitioned into 2,2,4-trimethylpentane prior to quantification by gas chromatography-mass spectrometry. The method was validated at 0.02 and 0.1 mg kg^-1 amitraz (well below MRL requirements) with a lowest calibrated level (LCL) for 2,4-dimethylaniline of 0.002 mg kg^-1 (equivalent to 0.0024 mg kg^-1 amitraz). A single partition step yielded recoveries of ∼60% (with % CV values in the range 3.3-8.2), which is satisfactory for screening purposes. A second partition increased recoveries by 10-20%, making the method suitable for the quantification of residues.     

双甲脒胶体金免疫快速检测试纸条研制及其在蜂蜜中的应用

目的 基于胶体金免疫层析原理研制双甲脒快速检测试纸条,评价其在蜂蜜检测中的应用效果。方法 使用双甲脒-BSA偶联物作为人工抗原免疫小鼠获得单克隆抗体,制备胶体金微孔试剂,使用双甲脒-OVA偶联物和羊抗鼠IgG抗体分别作为试纸条的检测线和控制线,并对蜂蜜样品进行添加检测。结果研制的试纸条可以定性检测蜂蜜中双甲脒的残留,对蜂蜜中双甲脒的检测限为0.2mg/kg,检测用时约25min,,与双甲脒功能和结构相似的其他药物时无交叉反应,特异性较好。结论 本试验研制的试纸条适用于蜂场现场快速检测以及基层实验室中大量样本的筛查,为蜂蜜中抗生素残留控制提供有效监管手段。     

气相色谱-质谱法同时测定蜂蜜中的双甲脒及其代谢物残留

建立了一种用气相色谱．质谱法(GC-MS)测定蜂蜜中的双甲脒及其代谢物(2，4-二甲基苯胺)残留的方法。蜂蜜样品用pH为11．0的水溶液溶解，其中的双甲脒和2，4-二甲基苯胺残留用正己烷超声波提取后直接用GC-MS测定。样品添加浓度在10μg／kg～200μg／kg时，双甲脒和2，4-二甲基苯胺的添加回收率在60％～120％之间，检出限均为10μg／kg。     

双甲脒合成反应动力学的研究

本文对２，４－二甲苯胺和原甲酸三乙酯反应合成Ｎ－（２，４－二甲苯基）亚胺基甲酸乙酯的反应过程进行了动力研究，利用孤立法和初始速率法求出了反应中级数α等于０．７５４，原甲酸（三）乙酯的反应级数β等于１，同时探讨了催化剂用量对反应速度的影响；结合对反应中副反应的研究，对反应机理进行了探讨。     

合成双甲脒新工艺的研究

本文通过试验研究，将国内外生产双甲脒普遍采用的三步法改进为一步法合成新工艺，通过及时蒸出副产物，减少２，４－二甲苯胺的用量和采用制的复合催化剂等一系列抑制副反应的措施，使产品的纯度达９５％以上，总收率比现行工艺提高１３．３％，比国外报道的文献值提高１０％并且缩短了工艺流生产流程，简化操作，减少三废，节省５０％的设备费用，该项科技成果有较为广阔的应用前景。     

牛奶中双甲脒检测方法的研究

目的 建立气相色谱法检测牛奶中双甲脒的快速检测方法。方法 试样中的双甲脒经酸水解成2,4-二甲基苯胺,碱化后用正己烷提取,七氟丁酸酐衍生,气相色谱-电子捕获检测器检测,外标法定量。结果 该方法检测双甲脒回收率范围在83.6%～97.4%之间,相对标准偏差在1.02%～4.23%之间,最低检出限为5ug/kg。结论 该方法简单、快速、分离度好,适用于批量样品的测定。     

优化气相色谱法检测牛奶中双甲脒残留标志物

目的改进国标中的气相色谱法测定牛乳中双甲脒残留标志物残留的前处理与色谱条件。方法样品使用1 mol/L的盐酸溶液提取,10000 r/min离心转速离心5 min,取上清液使用固相萃取(solid-phase extraction,SPE)小柱过滤净化。对气相色谱的色谱条件进行优化,使用外标法定量。结果通过使用优化处理条件,该方法的线性范围在10~400 ng/m L,线性关系良好。添加5、10、25?g/kg浓度水平,回收率均在90.5%~100.2%之间,相对标准偏差为1.4%~3.2%。结论改进后的方法回收率高、准确性高,对牛乳中双甲脒残留物的检测具有重要意义。     

Degradation of the acaricides abamectin, flufenoxuron and amitraz on Saudi Arabian dates

Degradation of the acaricides abamectin, flufenoxuron and amitraz on date palms, Phoenix dactylefera var. Nabout Seif, grown in Saudi Arabia was studied during the post-harvest interval (PHI) under the local weather and soil conditions. The initial deposit of abamectin residues on dates was 0.09 mg/kg, which declined to 0.03 (66%) and 0.02 mg/kg (88%) after 7 and 14 days of spraying, respectively (PHI = 10 days, MRL = 0.03 mg/kg). The initial deposit of flufenoxuron was 0.68 mg/kg and declined to 0.25 (68%), 0.07 (90%) and 0.03 mg/kg (96%) after 16, 52 and 60 days, respectively (PHI = 50 days, MRL = 0.1 mg/kg). Finally, the initial deposit of amitraz was 0.34 mg/kg which declined to 0.02 mg/kg (95%) and was not detected (100%) after 21 and 30 days, respectively (PHI = 28 days, MRL = 0.01 mg/kg). The acceptable daily intake (ADI) for fruits and vegetables set by FAO/WHO for the three acaricides tested was based on regular and average consumption of fruit, however, in Saudi Arabia, and other neighboring countries, natives consume more date (more than 10 times) than an average person living outside this region. Such high date consumption could lead to a higher risk of exposure to pesticides, especially in children and other vulnerable individuals.