摘要
【目的】为评价联苯肼酯在柑橘中的农药残留安全性,研究联苯肼酯与抗坏血酸还原反应后,标准溶液放置时间及保存温度、光照对检测结果的影响。【方法】建立了高效液相色谱分析方法,并将该分析方法应用于联苯肼酯在柑橘中消解动态和最终残留规律的研究。【结果】还原后的联苯肼酯标准溶液在冷藏条件下贮存,5 d内保持稳定。联苯肼酯在柑橘中均消解较快,在湖南、广州、贵州三地柑橘全果样品中半衰期分别为2.31、2.66、1.92 d。按推荐剂量和推荐使用最大剂量兑水喷雾施药2~3次,联苯肼酯在柑橘全果和橘皮中最高残留量分别为0.093、0.663 mg·kg-1。【结论】采用抗坏血酸还原联苯肼酯检测样品时,处理后的样品应避光冷藏贮存,5 d内分析。联苯肼酯在柑橘中最终残留量均低于国家标准《食品中农药最大残留限量》（GB2763-2014）最大残留限量标准（柑橘0.7 mg·kg-1）,收获的柑橘食用相对安全。
[ Objective ] Bifenazate （C17H20N203）is a novel carbazate acaricide discovered by Uniroyal Chemical （now Chemtura Corporation）. It has been widely used in the prevention and control of phytophagous mites infesting agricultural and ornamental crops. It is one of the best agents to control phytophagous mites in citrus. Therefore, it is important to evaluate bifenazate residues in citrus. In analysis of bife- nazate, ascorbic acid reduction was used for sample processing, but ascorbic acid is unstable and susceptible to breakdown by high temperatures, ultraviolet irradiation, alkaline condition and oxidants. In this concern, we examined the stability of the reduction product of bifenazate by ascorbic acid during storage in order to guarantee the accuracy of the analysis and evaluation. [Methods] In 2014, experiments were carried out in Changsha, Tuyun and Guangzhou to examine the dynamics of bifenazate degradation and the final residues. The tested varieties were Miyagawa No. 1, Citrus unshiu Marc and Luogang orange. For tracing the dynamics of chemical degradation, four plots were set including a control plot, and each plot had protection rows and 3 trees. Trees in plots 1 to 3 were sprayed once with 1 667-time diluent of 30% bifenazate. Samples were collected at 2 h, 1 d, 2 d, 3 d, 5 d, 7 d, 10 d, 14 d, 21 d, 28 d and 35 d after treatment. For final residue tests, samples sprayed with 1667- or 2 500-time diluent of 30% bifenazate for two or three times were collected 20 and 30 days after the final spray. The samples were extracted with acetonitrile and purified using Florisil adsorption column and 0.2% ascorbic acid-acetoni- trile （1：4, V/V）, and detected with HPLC-UVD, which was equipped with an Inertsil ODS-SP chromato- graphic column （250 mm×4,6 mm, 5 μm）. The mobile phase Was methanol： water=65：35 with a flow rate of 1.0 mL·min^-1. The sample injection volume was 20μL and the detection wavelength was 245 nm. The results suggested that the fortified recovery and variation coefficient o
出处
《果树学报》
CAS
CSCD
北大核心
2016年第11期1431-1438,共8页
Journal of Fruit Science
基金
农业部农药残留资助基金(2012P091)
