三氟啶磺隆钠盐在甘蔗及土壤中的残留动态研究

采用高效液相色谱(HPLC)测定了三氟啶磺隆钠盐在甘蔗及土壤中的消解动态和最终残留。样品用甲醇提取,二氯甲烷萃取,弗罗里硅土柱净化,高效液相色谱仪检测定量。结果表明:该方法回收率为81.12%～96.20%;变异系数为2.39%～5.86%。仪器最小检出量为0.4 ng,最小检出浓度:甘汁和甘叶为0.025 mg/kg,土壤为0.012 5 mg/kg。三氟啶磺隆钠盐在甘蔗叶和土壤中消解较快,其半衰期分别为3.26～5.41 d和7.19～8.51 d。药后120 d降解率:植株>99.5%,土壤>97.3%。我国尚未制定三氟啶黄隆钠盐在甘蔗上的MRL值,参照美国规定磺酰脲类除草剂敌草隆在甘蔗中的最大残留限量为0.5 mg/kg,在我国南方蔗区,按照推荐剂量施药1次,药后120 d(成熟时)收获是安全的。

Residue Dynamics of Trifloxysulfuron Sodium in Sugarcane and Soil

A high performance liquid chromatography was conducted to reveal the residue dynamics and final residues of trifloxysulfuron sodium in sugarcane and soil.Samples were extracted with methanol and dichloromethane were cleaned up by passing through florisil column,and were determined by HPLC.The results showed that the average recoveries,coefficients of variation were 81.12%～96.20%,2.39%～5.86%,respectively.The minimum detectable amount was 0.4 ng.The minimum detectable concentration were 0.025 mg/kg in sugarcane juice and leaves,it was 0.012 5 mg/kg in soil.The trifloxysulfuron sodium degraded rapidly in sugarcane and soil.The half-life of trifloxysulfuron sodium in sugarcane and soil were 3.26～5.41 d and 7.19～8.51 d,respectively.More than 99.5% in sugarcane and 97.3% in soil degraded after the trifloxysulfuron sodium was sprayed for 120 d.There was no stipulation about the maximum residue limit of trifloxysulfuron sodium in sugarcane in China.With reference to the MRL(0.5 mg/kg)of America,trifloxysulfuron sodium was safe when applying recommended dose.