一种新型的杀螟丹分析方法及其在稻田杀螟丹残留动态分析中的应用

建立了一种水稻植株、糙米、稻壳、土壤和田水中的杀螟丹气相色谱-火焰光度检测(GC-FPD)方法。样品中的杀螟丹使用稀盐酸提取,然后在碱性条件下使用氯化镍(NiCl₂)将其衍生为沙蚕毒素,最后采用在线连接的支撑液液萃取(SLE)和固相萃取(SPE)进行萃取和富集。在优化好的条件下,杀螟丹在5种空白样品中低、中、高3种添加浓度的回收率为80.0%~114.4%,相对标准偏差(RSD)小于13.7%,表明所建立的方法具有良好的准确度和精密度。将所建立的方法用于大田条件下杀螟丹的残留动态分析,为建立杀螟丹的最大残留限量(MRL)提供参考,同时也可对农药施用技术的安全性进行评价。

Development of a novel analytical method of cartap and its application to the residue and dissipation analysis of cartap in paddy field

Cartap has been widely used as a highly effective pesticide in rice fields for the control of rice stem borer and leaf folde. In this paper, a novel analytical method of cartap in rice plants, husked rice, rice hull, soil and water was developed by gas chromatography-flame photometric detector (GC-FPD). Cartap in these sample matrices was first extracted with dilute hydrochloric acid solution, and then derivatized to nereistoxin with nickel chloride (NiCl₂) under basic condition. At last, nereistoxin was extracted and concentrated by on-line combination of supported liquid-liquid extraction (SLE) and solid phase extraction (SPE). Under the optimal conditions, the recoveries of cartap in these sample matrices spiked at three levels ranged from 80.0% to 114.4% with relative standard deviations (RSDs) less than 13.7%, indicating good accuracy and precision of our proposed method. The proposed method was then applied to the analysis of residue and dissipation of cartap in rice plants, husked rice, rice hull, soil and water under field conditions. The results can provide reference for the establishment of the maximum residue level (MRL) of cartap and estimation of safety of pesticide application technology.