Simultaneous Detection Of Imidacloprid And Carbendazim In Crops With HPLC Method

Imidacloprid is a super-efficient neonicotinoid pedticide. Carbendazim is a benzimidazolic fungicide. They are widely used to control agriculture crop diseases and insect pests.The pesticide residue problem not only affect on agricultural export trade, but also impact on consumer food safety, so it is significant to detect the content of imidacloprid and carbendazim in agriculture crops. At present, there have been mang reports on the residue analysis of imidacloprid or carbendazim in agriculture crops at home and abroad, but mostly been single-residue analysis. The simultaneous detection of imidacloprid and carbendazim is rarely reported and the sample preparation methods are complicated and narrow in application and so on.Two different pretreatment procedures were discussed and compared in this paper, and the solid phase extraction was confirmed as the main extraction methods. The samples were ultrasonic extracted with acetone, cleaned up by solid phase extraction and analyzed by reversed phase high performance liquid chromatography with ultraviolet detector.Firstly, A iquid-liquid extraction-high performance liquid chromatographic detection method was disscussed for the stimultaneouse analysis of imidacloprid and carbendazim pesticide residue. Samples were ultrasonic extracted with acetone for 30 min, cleaned up by adjusting the pH of the solvent. The HPLC conditions were that methanol-0.02 mol/L phosphate buffer (pH=7.4)=25:75(v:v) as mobile phase and the wavelength of UV detection at 278 nm. Under the optional experimental conditions, we drawed the standard curves of imidacloprid and carbendazim and obtained the regression equation. The regression equations of imidacloprid and carbendazim respectively were Y=0.7422X-0.0316(R=0.9999) and Y=0.6145X-0.2146(R=0.9978). RSDs of peak area of imidacloprid and carbendazim were 0.17% and 0.89% respectively. The detection limits of imidacloprid and carbendazim were 0.01mg/kg and 0.02mg/kg respectively.Secondiy, A solid phase extraction-high performance liquid chromatographic detection method was disscussed for the stimultaneouse analysis of imidacloprid and carbendazim pesticide residue and the solid phase extraction conditions are optimized. Samples were extracted with acetone, cleaned up by CN solid-phase extraction column with 20% methanol water as sample solvent,8 mL A solution as leacheate,2 mL 60% methanol aqueous solution as the eluent. Finally, the extraction effects of liquid-liquid extraction and solid phase extraction were compared, then the solid phase extraction was confirmed as the main extraction methods.Thirdly, the contents of imidacloprid and carbendazim in selected tobacco and cigarette samples had been determined under the optional experimental conditions. The results were that the contents of imidacloprid and carbendazim in tobacco sample were 0.208 mg/kg and 0.584 mg/kg respectively; the contents of imidacloprid and carbendazim in cigarette sample were 0.784 mg/kg and 1.19 mg/kg respectively. In addition, the fortified average recoveries of imidaclorpid and carbendazim in tobacco respectively were 88.4%,88.9% and the fortified average recoveries of imidaclorpid and carbendazim in cigarette samples respectively were 89.0%,89.5%. Then ten kinds of tobacco samples and five commercial cigarette samples were determined and compared and analyzed simply.Finally, the contents of imidacloprid and carbendazim in tomato, cucumber, melon, apple, pear, rice samples were detected under the optional experimental conditions. The results were that the contents of imidacloprid in tomato, cucumber and apple samples were 1.92 mg/kg,0.873 mg/kg and 0.927 mg/kg, respectively; the contents of carbendazim in tomato and pear samples were 1.96 mg/kg and 2.07 mg/kg, respectively; the imidacloprid and carbendazim pesticide residues in melon and rice samples were not detected. In addition, the fortified average recoveries of imidacloprid respectively were 86.2%,86.4%,84.6%,85.0%,84.4%,87.2% and the fortified average recoveries of carbendazim respectively were 85.8%,85.4%,85.5%,86.3%, 87.7%,86.3% in the tomato, cucumber, melon, apple, pear, rice samples.