龙胆草中农药嘧霉胺残留动态的研究

Study on Residue Trends of Pesticides Pyrimethanil in Gentian

目的:建立适合龙胆草中嘧霉胺残留的分析方法,探讨龙胆中嘧霉胺残留和消解规律。方法:本研究首次采用高效液相色谱法研究龙胆中嘧霉胺pyrimethanil的残留动态,对同一批经施药8次的龙胆按不同的时间间隔进行分批采样,优化样品制备方法和色谱条件并进行分析。结果:建立了高效液相色谱法测定龙胆中嘧霉胺残留量的方法,龙胆中嘧霉胺含量随时间消减,消解方程C=1.4569-0.9105exp(59.2146t-2.7442),半衰期为6.65天。结论:本研究建立了利用高效液相色谱法测定龙胆中嘧霉胺残留量的可靠方法,建立的消解方程能准确描述龙胆中嘧霉胺消解规律。通过减少用药次数和交替用药,延长采收的安全间隔期,可以降低农药残留。

The study aimed to establish asuitable method for analyzing pyrimethanil in gentian, in order toexplore the residue trends of pyrimethanil in gentian and its degradation dynamics. The high performance liquid chromatography（HPLC） method was the first to be performed in this study tolearn the residue trends of pyrimethanil. Prior to sampling gentian at different time intervals, the samples were spreaded by pesticides for eight times at the same timeline. The preparation method and chromatographic conditions were optimized and analyzed. As a result, the HPLC method that detected the residues of pyrimethanil in gentian was established. The content of pyrimethanil in the gentian samples degradated over time, and its resolution equation was C=1.4569-0.9105exp（59.2146t-2.7442） with the half-time of 6.65 days. It was concluded that HPLC method for determining the pyrimethanil residues of gentian was reliable, and the resolution equation accurately described the principle of pyrimethanil degradation in gentian. By reducing the frequency and alternating theutilization of pesticide, prolonging the security intervals of harvesting may reduce the pesticide residues.