Determination of Ethoxysulfuron and Benzobicyclon in Rice by LC-MS/MS
To establish a method for simultaneous ethoxysulfuron and benzobicyclon residues in rice by LC-MS/MS.The samples were vortexed with acetonitrile solution,NaCl salted out,purified with 0.25 g MgSO4,0.05 g PSA and 0.05 g C18,electrelectrospray ionization(ESI+)positive ion scanning,multiple reaction monitoring(MRM)mode,and external standard method.The results showed that the correlation coefficient of 2 pesticides were higher than 0.99 in the concentration ranged from 0.001 to 0.5 µg/L.When the spiked level ranged from 0.01 to 1.0 mg/kg,the average recovery rates of 2 pesticides in rice ranged from 84%to 107%,and the RSD ranged from 1%to 8%.When the spiked level ranged from 0.05 to 2.5 mg/kg,the average recovery rates of 2 pesticides in rice hull ranged from 86%to 101%,and the RSD ranged from 2%to 8%;in rice plant ranged from 87%to 99%,and the RSD ranged from 6%to 11%.The limits of quantitation of ethoxysulfuron and benzobicyclon in rice samples were 0.01 mg/kg and in rice hull and rice plant samples were 0.05 mg/kg.