苦参碱在黄瓜和土壤中的检测方法及其残留动态研究

为了解苦参碱在黄瓜和土壤中的残留状况及消解动态,建立了苦参碱在黄瓜和土壤中的气相色谱分析方法,并在天津和安徽两地开展了为期两年的苦参碱在黄瓜和土壤中残留状况和消解动态规律田间试验研究。结果表明,采用无水乙醇超声提取黄瓜和土壤中的苦参碱,使用大孔吸附树脂净化,甲醇定容,气相色谱带氮磷检测器(NPD)进行测定,外标法定量,在0.25～1.0mg·kg-1添加水平范围内,苦参碱在黄瓜和土壤中的平均回收率为78.32%～98.06%,变异系数为3.72%～7.44%;黄瓜和土壤中苦参碱的最小检出量均为1.36×10-12g,最低检出浓度为0.004mg·kg-(1黄瓜)、0.008mg·kg-(1土壤)。田间试验结果表明,苦参碱在黄瓜和土壤中的残留消解动态符合方程Ct=C0e-kt;苦参碱在黄瓜和土壤中的降解半衰期分别为5.19～7.24d和6.70～9.18d。在黄瓜中施用0.3%苦参碱乳油,其制剂施药量为0.18～0.27g·m-2,施药3～4次,两次施药间隔期为7d,距收获期为1d时,苦参碱在黄瓜中的残留量为0.1256～1.2071mg·kg-1,土壤中的残留量为0.0450～0.1837mg·kg-1。目前...

Residue Detection and Degradation of Matrine in Cucumber and Soil

In order to know clear residue pollution and degradation trends of matrine in cucumber and soil,an analytical method of gas chromatography was established for determining matrine residue in soil and cucumber,and the residue and degradation of matrine were also investigated.Matrine residue was extracted by methanol,then extracted by dichloromethane,and determined by gas chromatography equipped with a NPD detector.The average recoveries of the matrine standards within a range of 78.32%～98.06% at three spiking levels from 0.25 to 1.0 mg·kg-1 with their relative standard deviations of 3.72%～7.44% in soil and cucumber.Limit of detection was 1.36×10-12 g and the lowest concentrations detected were 0.004 mg·kg-1 in cucumber and 0.008 mg·kg-1 in soil,respectively.An control and contrast trial experiments were done in Tianjin municipal and Anhui Province.The degradation of matrine in cucumber and soil could be described with equation:Ct=C0e-kt.The half-life of matrine turns to be 5.19～7.24 d in cucumber and 6.70～9.18 d in soil,respectively.According to the research,when 0.3% Matrine EC was applied three and four at an interval of 7 d with the dosages of 0.18～0.27 g·m-2 during its whole culture process.At the 1st day after the last application,the final residues of the matrine were 0.125 6～1.207 1 mg·kg-1 in cucumber and 0.005 0～0.183 7 mg·kg-1in soil.So far,MRLs is still no formulated about matrine in cucumber or related farm products at home and abroad,so the experimental results provide an important scientific data for register and secure application regulation formulate of 0.3% Matrine EC,and have an important effect for protect agricultural environment and human health.