Determination of Multiresidue of Pesticide in Chrysanthemum by Magnetic Fullerene Dispersive Solid Phase Extraction with Liquid Chromatography-Tandem Mass Spectrometry

Magnetic fullerene (Fe3O4@SiO2@C-60) was synthesized as a solid-phase extraction adsorbent for extraction and enrichment of pesticides in Chrysanthemum. Based on this, anultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method was developed for determination of nine kinds of pesticides, including cyprodinil, zoxamide, tolfenpyrad, azoxystrobin, pyraclostrobin, trifloxystrobin, fenpyroximate, pyridaben and phoxim in edible chrysanthemum. The results showed that the Fe3O4@SiO2@C6(0 )had obvious adsorption to cyprodinil, zoxamide, tolfenpyrad, azoxystrobin, pyraclostrobin, trifloxystrobin, fenpyroximate, pyridaben and phoxim. The influence factors of magnetic dispersion solid phase extraction were investigated, and it was found that a best extraction was obtained under the optimal conditions such as 30. 0 mg of Fe3O4@SiO2@C-60 as adsorbent, extraction for 20 min under shaking, separation of the Fe3O4@SiO2@C-60 by an external magnetic field, and elution two times with 1 mL of ethyl acetate. The result showed that Fe3O4@SiO2@C(60 )had good stability and reusability. All of the tested pesticides showed good linear relationship in the range of concentration 0.005 - 0.1 mg/L with correlation coefficients of greater than 0.999. The detection limits and the quantitation limits of nine target pesticides were in the range of 0.001 - 0.003 mg/kg and 0.003-0.01 mg/kg, respectively. When the addition levels of the pesticides were 0.01, 0.05 and 0.10 mg/kg, the recoveries of the method ranged from 71. 0% to 94. 6% with the relative standard deviations (n=6) ranging from 4. 6% to 11. 3%. The method was simple, sensitive, fast and with low cost, and suitable for the accurate qualitative and quantitative determination of nine pesticides in chrysanthemum.