腈菌唑在荔枝及土壤中的残留动态研究

为明确腈菌唑在荔枝及土壤中的消解情况和环境评价，通过田间试验和气相色谱分析技术研究了40%腈菌唑可湿性粉剂在荔枝上及土壤中施用后的消减动态。样品用甲醇提取，乙酸乙酯液液分配萃取、弗罗里硅土柱层析净化，气相色谱法电子捕获检测器测定了腈菌唑在荔枝上和土壤中的残留量。广东、广西两地试验结果表明：腈菌唑在荔枝及土壤中的降解过程均符合一级动力学方程，在荔枝和土壤中的半衰期分别为2.2~2.5天和2.8~3.1天。在有效成分为100 mg/kg剂量下，施药3次，药后7天，腈菌唑在荔枝上的最终残留量均小于2 mg/kg，建议其在荔枝上的最大残留限量值（MRL值）暂定为2 mg/kg。

Residual Dynamics of Myclobutanil Fungicides in Litchi and Soil

Field trial and gas chromatography test were conducted in 2008-2009 in Guangxi and Guangdong to study the residual decline of myclobutanil in the litchi（cv.Heiye）and soilto.The pesticide was extracted using methanol from samples,cleaned by the column of florisil and determined by capillary column gasc hromatography with electron capture detector（ECD）.The results in Guangdong and Guangxi showed that the decline of myclobutanil in litchi and soil followed the first-kinetic equation,and the half-lives were 2.2-2.5d ays in litchi and 2.8-3.1 days in soil,respectively.The litchi was sprayed three times with 40%myclobutanilW P according to the recommended dosage 100 mg/kg.The determination results revealed that the myclobutanilr esidues in litchi were all below 2 mg/kg.It was recommended that the maximum residue limits of myclobutanil in litchi were set at 2 mg/kg.