Watanabe Minae, Ueyama Jun, Ueno Eiji, Ueda Yuko, Oda Masaya, Umemura Yuko, Tanahashi Takashi, Ikai Yoshitomo, Saito Isao
a Department of Pathophysiological Laboratory Science, Field of Radiological and Medical Laboratory Sciences , Nagoya University Graduate School of Medicine , Nagoya , Japan.
b Department of Hygienic Chemistry , Aichi Prefectural Institute of Public Health , Nagoya , Japan.
Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2018 Jul;35(7):1316-1323. doi: 10.1080/19440049.2018.1451659. Epub 2018 May 23.
Dinotefuran is an insecticide belonging to the neonicotinoid class, which is frequently used to control pests in paddy rice owing to its permeability and effectiveness against sucking insects. Since 2002, this insecticide has been commercially available in Japan, and has become controversial due to its high detection frequency in brown rice for primary consumption. In this study, the effects of processing and cooking on the reduction of dinotefuran residues in commercially available brown rice were investigated. Boiled rice is difficult to homogenise and extract with acetonitrile. Using pre-freezing and cryogenic milling with powdered dry ice, dinotefuran in boiled rice was extracted well. A measurement method comprising sample preparation (acetonitrile extraction, gel permeation chromatography, and SPE) and detection with anLC-MS/MS system was used. In 10 out of 25 commercial brown rice samples, dinotefuran was detected at a concentration of 0.04 μg/g (mean), which was more than the limit of quantitation of 0.01 μg/g. The dinotefuran levels were significantly less than the MRL of 2 μg/g in Japan. Even after polishing, washing, and boiling, dinotefuran was detected in 10 brown rice samples, with mean residue levels of 74.7%, 60.8%, and 39.6%, respectively, of the original concentration in brown rice. Based on these data, the processing factor of dinotefuran in boiled rice has been estimated to be approximately 0.4. Dinotefuran residues were reduced in the boiled rice, but less so than other pesticides. Although the maximum daily intake of dinotefuran in boiled rice was 0.0065 mg/person/day, its percent ratio to the ADI of dinotefuran in Japan was less than 0.05%. These results suggest that the daily intake of dinotefuran from rice might not be a critical problem at present, in spite of its relatively high detection frequency in boiled rice.
呋虫胺是一种新烟碱类杀虫剂，因其对刺吸式昆虫的渗透性和有效性，常用于控制水稻害虫。自2002年以来，这种杀虫剂在日本已商业化销售，由于其在主要消费的糙米中检测频率较高，已引发争议。在本研究中，调查了加工和烹饪对市售糙米中呋虫胺残留量减少的影响。煮米饭难以用乙腈进行均质化和提取。通过预冷冻和使用干冰粉末进行低温研磨，煮米饭中的呋虫胺得到了良好的提取。采用了包括样品制备（乙腈提取、凝胶渗透色谱和固相萃取）以及用液相色谱-串联质谱系统检测的测量方法。在25个市售糙米样品中，有10个检测到呋虫胺，浓度为0.04μg/g（平均值），超过了0.01μg/g的定量限。呋虫胺水平显著低于日本2μg/g的最大残留限量。即使经过抛光、洗涤和煮沸后，仍在10个糙米样品中检测到呋虫胺，残留平均水平分别为糙米原始浓度的74.7%、60.8%和39.6%。基于这些数据，估计煮米饭中呋虫胺的加工因子约为0.4。煮米饭中的呋虫胺残留量有所减少，但比其他农药减少得少。尽管煮米饭中呋虫胺的最大日摄入量为0.0065mg/人/天，但其占日本呋虫胺每日允许摄入量的百分比小于0.05%。这些结果表明，尽管呋虫胺在煮米饭中的检测频率相对较高，但目前从大米中摄入呋虫胺可能并非关键问题。
