稻谷中吡虫啉农药残留量的固相萃取高效液相色谱测定

Determination of Imidacloprid in Rice by Solid Phase Extraction-HPLC

介绍了用高效液相色谱法测定稻谷中吡虫啉农药残留量的方法 ,样品经乙腈超声提取 ,固相萃取小柱快速净化提取物 ,HPLC -UV分离测定 ,外标法定量 ,方法的定量下限为0.005×10-6(w) ,回收率>80 % ,相对标准偏差<7 %。

A method was developed for the determination of imidacloprid in rice by HPLC-UV. Imidacloprid was extracted with acetonitrile in an ultrasonic bath, then purified through SPE ENVI _ Carb and LC _ Alumina N column(3 mL). The eluate was evaporated under air and the residue was dissolved in 1 mL acetonitrile. Chromatographic separation was performed with SUPELCO Discovery C18(25 cm×4.6 cm ID, 5 μm) column with eluent consisting of acetonitrile-0.2%(w) acetic acid(2∶3 by volume), and the eluate was monitored at λmax=269 nm. The content of imidacloprid was determined by external standard methed. A lower limit of detectability of 0.005×10-6(w), recovery of more than 80% and RSD of less than 7% were obtained.