摘要:
[目的]研究多效唑在花生和土壤中的残留及消解动态,为在花生上安全使用多效唑提供科学依据.[方法]所有样品用乙腈提取,土壤经液液分配净化,花生样品经弗罗里硅土层析柱和石墨化炭黑净化后,用带氮磷检测器的气相色谱仪检测,外标法定量,并进行两年3地的田间残留试验,探究多效唑在花生仁、花生壳、花生植株和土壤中的残留及消解动态.[结果]多效唑的气相色谱—氮磷检测法最低检出量为0.15 ng,在土壤、花生仁、花生壳和花生植株的最低检出浓度为0.03~0.05 mg/kg.在添加浓度水平为0.05、0.50和1.00 mg/kg时,多效唑在土壤、花生仁、花生壳和花生植株中的平均回收率分别为72.5%~108.8%、95.9%~108.3%、81.8%~109.6%和75.2%~96.7%,相对标准偏差分别为5.1%~14.3%、5.8%~8.7%、4.6%~9.3%和5.0%~8.9%.多效唑在土壤和花生植株中的降解半衰期分别为2.4~14.3和1.0~5.7 d.广西、湖南和河南3地成熟花生中多效唑的最终残留量未检出.[结论]以气相色谱—氮磷检测法检测多效唑的灵敏度、准确度及精密度均符合农药残留分析要求,可用于花生和土壤中多效唑残留检测.在花生下针期间按照推荐剂量90~120 g a.i./ha使用15%多效唑悬浮剂对水施用1次,收获时无多效唑残留,对花生安全.
关键词:
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多效唑
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花生
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消解动态
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残留
Abstract:
[Objective]Residues of paclobutrazol and its degradation dynamics in peanut soil were studied in order to provide references for the rational use of paclobutrazol in peanut cultivation.[Method]Samples were extracted with aceto-nitrile,and soil was purified by liquid-liquid separation. Peanut samples were purified by Cleanert Florisil and graphitized carbon black,then determined by gas chromatograph with nitrogen phosphorous detector using external standard method. Through residue experiments during two years in three places,residues and degradation dynamics of paclobutrazol in pea-nut kernel,peanut shell,peanut plant and soil were researched.[Result]The minimum detectable quantity of paclobutra-zol in gas chromatography-nitrogen and phosphorus detection method was 0.15 ng,and the minimum detectable quantity in soil,peanut kernel,peanut shell and peanut plant was 0.03-0.05 mg/kg. When the concentration of paclobutrazol were 0.05,0.50 and 1.00 mg/kg,the average recovery was 72.5%-108.8% from soil,95.9%-108.3% from peanut kernel, 81.8%-109.6%from peanut shell and 75.2%-96.7%from peanut plant. The relative standard deviation were 5.1%-14.3%(soil),5.8%-8.7%(peanut kernel),4.6%-9.3%(peanut shell)and 5.0%-8.9%(peanut plant). The degradation half-life of paclobutrazol was 2.4-14.3 d in soil and 1.0-5.7 d in peanut plant. The final residues of paclobutrazol in peanut from Guangxi,Hunan and Henan were not detected.[Conclusion]The sensitivity,accuracy and precision of gas chro-matography-nitrogen and phosphorus detection method in detecting paclobutrazol meet the requirements for pesticide resi-due analysis,which can be applied to the detection of paclobutrazol residue in paclobutrazol and soil. At acicula forming stage,applying recommended dosage(90-120 g a.i./ha)of 15%paclobutrazol SC once is safe for peanut with no residue at harvest.
百度学术
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