大米中环已烯酮类除草剂残留量的测定

建立了大米中环己烯酮类除草剂残留量同时测定的液相色谱-质谱/质谱法。试样中残留的环己烯酮类除草剂用酸性乙腈高速匀浆提取，提取液经N-丙基乙二胺（PSA）、十八烷基硅烷（ODS）和石墨化炭黑净化，用液相色谱-质谱／质谱仪检测和确证，外标法定量。环己烯酮类除草剂的浓度在0．0025～0．1000μg·mL^-1范围内时，线性关系良好，8种环己烯酮类除草剂的相关系数为0．9947～0．9992。在0．005～0．050mg·kg^-1浓度范围内，样品平均加标回收率在73．2％～107．0％之间，相对标准偏差为5．14％～10．15％。8种环己烯酮类除草剂的最低检出限均为0．005mg·kg^-1。

Determination of cyclohexanediones herbicide residues in rice

A method has been developed for the determination of cyclohexanediones herbicide residues in rice. The cyclohexanediones herbicide residues in the test sample are extracted with acidic acetonitrile by means of high speed homogenization. The residues is cleaned up by primary secondary amine （PSA）, octadecylsilane（ODS） and graphitized carbon black. The residues is determined and confirmed by LC-MS/MS, using external standard method. The liner range was 0.0025-0.100μg·mL^-1 for cyclohexanediones herbicide. The correlation coefficients were 0.9947 -0.9992 for the eight cyclohexanediones herbicide. The average recoveries of cyelohexanediones herbicide in spiked samples ranged from 73.2%-107.0%, and the relative standard deviations were between 5.14% -10.15% at spiked levels of 0.005 -0.050mg ·kg^-1. The limit of detection was 0.005mg·kg^-1 for the eight cyclohexanediones herbicide.