呋虫胺在水稻中的残留消解及膳食风险评估

为评价呋虫胺在水稻中的残留消解行为和产生的膳食摄入风险,分别于2012和2013年在安徽、重庆和广西进行了规范残留试验,建立了高效液相色谱-紫外检测器(HPLC-UV)检测呋虫胺在水稻糙米、稻壳和植株中残留的分析方法,并对我国不同人群的膳食暴露风险进行了评估。样品经乙腈提取、Florisil柱层析净化,高效液相色谱-紫外检测器检测,外标法定量。结果表明:呋虫胺在糙米、稻壳和植株中的定量限(LOQ)均为0.05 mg/kg。在0.05~2 mg/kg添加水平下,呋虫胺的平均回收率在70%~100%之间,相对标准偏差(RSD)在0.5%~6.5%之间。呋虫胺在水稻植株中的消解符合一级动力学方程,半衰期为2.3~4.8 d,距末次施药后7 d糙米中的最大残留量为0.53 mg/kg,低于日本和国际食品法典委员会(CAC)规定的最大残留限量2和8 mg/kg。膳食摄入风险评价结果显示:我国各类人群的呋虫胺国家估计每日摄入量(NEDI)为0.438~1.087 μg/(kg bw·d),风险商值(RQ)为0.002~0.005,表明呋虫胺在糙米中的长期膳食摄入风险较低。

Dissipation, residues and dietary risk assessment of dinotefuran in rice

In order to evaluate the residue behavior and dietary intake risk of the dinotefuran applied to rice, the residual trial of dinotefuran in rice were carried out in Anhui, Chongqing and Guangxi in 2012 and 2013, respectively. A novel method for the residue determination of dinotefuran in rice, rice hull and rice straw was developed by using high performance liquid chromatography with ultraviolet detector (HPLC-UV). The dietary risk assessment to different populations based on data of dinotefuran residues in rice was investigated. The samples were extracted by acetonitrile, purified by florisil chromatographic column, detected by HPLC-UV. Results showed that: The limits of quantification (LOQs) in rice, rice hull and rice straw were 0.05 mg/kg. At fortified levels of 0.05 to 2 mg/kg, the average recoveries varied from 70% to100% with the relative standard deviation of 0.5% to 6.5%. The results indicated that the dissipation of dinotefuran in rice straw fitted to the first order kinetics with half-lives varied from 2.3 to 4.8 days. Terminal residues in rice were less than 0.53 mg/kg at the 7th days after the last application, which was below the MRL of Japan (2 mg/kg) and CAC (8 mg/kg). The national estimated daily intake (NEDI) was between 0.438-1.087 μg/ (kg bw·d) and the risk quotients (RQ) were between 0.002-0.005 for different populations in China, which indicated its low risk in rice.