25%咪鲜胺水乳剂在水稻上的残留动态研究

摘 要：建立了咪鲜胺在土壤和水稻中的残留量的气相色谱检测方法。样品用丙酮和无水硫酸钠提取,饱和氯化钠水溶液和二氯甲烷萃取，与吡啶盐酸盐进行衍生化反应，经浓硫酸净化，用气相色谱带电子捕获检测器(GC-ECD)检测，用外标法定量。结果表明：咪鲜胺在土壤和水稻中的添加水平在0.1~1.0 mg/kg时，添加回收率分别依次为91.7~97.6%、82.4~92.0%，相对标准偏差8.6~13.2%、4.8~14.0%。土壤、水稻中最小检出浓度均为(LOQ)0.01 mg/kg。咪鲜胺的水解产物2,4,6-三氯苯酚的最小检出量为(LOD)1×10-11 g。两年三地的残留试验结果表明：25%咪鲜胺水乳剂在水稻土壤中的残留消解半衰期：广西为4.1~7.1d、湖南长沙为4.7~8.3d、福建为3.4~4.3d；水稻中的残留消解半衰期：广西为2.1~3.0d、福建为3.3~3.8d、湖南为3.9~4.5d。不论高剂量750 mg/kg还是低剂量500 mg/kg处理, 水稻收获时在供试三地水稻中均未检出咪鲜胺。

关键词：咪鲜胺  2,4,6-三氯苯酚  水稻  残留分析  消解动态

 

Residue Dynamics of25％ Prochloraz Emulsion in Rice

Abstract:A method was developed to determine residues of prochloraz in Rice. Samples were extracted with acetone and dehydrated by anhydrous sodium sulfate. Prochloraz was previously derivatized with Pyridine hydrochloride. Combination of concentrated sulfuric acid cleanup process was favorable for the GC-ECD analysis. The recovery in Rice ranged from 91.7% to 97.6%, 82.4% to92.0%with the relative standard deviations of 8.6% to 13.2%, 4.8% to14.0%, respectively. The limit of detection (LOD) of the method was 1.0×10-11g. The limit of quantification (LOQ) was 0.01 mg/kg. The half life of prochloraz was 4.1~7.1d, 4.7~8.3 and 3.4~4.3 days in Rice and2.1~3.0, 3.3~3.8 and3.9~4.5days in soil of Guangxi, Hunan and Fujian province at two years, respectively. No prochloraz residues were detected in Rice samples at treatments of 500~750 mg/kg at harvest season.

Key words:  prochloraz;  2,4,6-TCP;  Rice;  esidue;  dynamaics

目  录

摘 要 1

关键词 1

1前言 2

2 材料与方法 2

2.1 主要仪器及药剂 2

2.2 分析方法 2

2.2.1 样品前处理 2

2.3 GC分析条件 3

2.4 标准溶液的配制 3

2.5 添加回收率的计算 4

2.6 田间试验 4

2.6.1 消解动态试验 5

2.6.2 最终残留试验 5

2.7 气候条件﹑土壤类型 5

3 结果与分析 6

3.1 标准曲线: 6

3.1.1 残留量计算公式 7

3.2 残留试验结果 7

3.2.1 25%咪鲜胺水乳剂在水稻植株、土壤和田水消解动态试验结果 7

3.2.2 25%咪鲜胺水乳剂在水稻植株、土壤和田水最终残留测定结果 15

3.3 结论及合理使用建议 17

3.3.1结论 17

3.3.2合理使用分析 17

参考文献 18

致  谢 20

附录 21

附录1 21