戊唑醇在苹果和土壤中的残留及消解规律研究

目的]建立GPC-GC/MS测定苹果和土壤中戊唑醇残留的方法。方法]采用GPC-GC/MS测定苹果和土壤中戊唑醇残留,并研究戊唑醇在苹果和土壤上的残留消解动态。结果]通过优化程序升温条件和选择合适的定量离子、定性离子,确定了最优的气相色谱及质谱条件:初始温度82℃保持5 min,然后以8℃/min程序升温至300℃,保持4.2 min;PTV进样口温度:初始温度120℃保持5 min,然后以100℃/min程序升温至250℃,保持31.7 min。离子源温度为200℃;接口温度为250℃。在优化的气相色谱及质谱条件下,苹果中残留的戊唑醇和杂质能够得到很好的分离、定性及定量,线性关系良好,相关系数为0.999。从提取溶剂种类和吸附剂种类2个方面对Qu ECh ERS方法进行优化,最终确定乙腈为提取液,用N-丙基乙二胺(PSA)为萃取净化吸附剂,经涡旋、离心、氮吹浓缩,用乙酸乙酯定容。利用在线GPC技术进一步净化样品,同时利用PTV大体积进样和进样口程序升温方式提高了检测灵敏度。方法的回收率为75%~109%,相对标准偏差为3.1%~9.4%。通过田间动态试验得到戊唑醇的消解动态方程,其在苹果上的半衰期为13.9 d。结论]该方法检出限低、精密度高、满足农药残留分析要求,可用于检测苹果和土壤中戊唑醇残留。

Study on Residue and Dissolving Dynamic of Tebuconazolein in Apple and Soil

Objective] The aim was to establish a GPC-GC/MS determination method for residue of tebuconazolein in apple and soil.Method] We determined the residue of tebuconazolein in apple and soil by GPC-GC/MS,and studied the dissolving dynamic of tebuconazolein in apple andsoil.Result] The optimal conditions of GC-MS were as followed:the initial temperature 82 ℃ was kept for for 5 min,and then reached 300 ℃ by 8 ℃/min for 4.2 min.The sampling temperature of PTV was 120 ℃ for 5 min,and then reached 250 ℃ by 100 ℃/min for 31.7 min.Ion source temperature was 200 ℃,and the interface temperature was 250 ℃.Under the optimal conditions,the tebuconazolein residue in apple could be isolated with impurities well,the linear relationship was good,and the correlation coefficient was 0.999.The method of QuEChERS was optimized from two aspects of extraction solvent type and adsorbent type.Finally it is confirmed that acetonitrile was as extract liquid,PSA was as extraction and purification of adsorbent,ethyl acetate was used for constant volune after whirlpool,centrifugal and nitrogen blow enrichment.The samples were purified by online GPC technology,and the detection sensitivity was improved by PTV bulk sample and injection process heats up.The Recovery rate of the method was 75％-109％,and the relative standard deviation was 3.1％-9.4％.Finally the dynamic equations of pentazolol were obtained by field dynamic test,and the half-life of the apple was 13.9 d.Conclusion] The method had low detection limit and high precision,can satisfy the demand of pesticide residue analysis,so it can be used for determine tebuconazolein in apple and soil.