Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, P. R. China.
Australian Centre for Research on Separation Science, School of Chemistry, Monash University, Clayton, Melbourne, Australia.
J Sep Sci. 2019 Apr;42(8):1610-1619. doi: 10.1002/jssc.201801159. Epub 2019 Mar 6.
In this work, a method for the analysis of benzoylurea insecticides, including hexaflumuron, flufenoxuron, lufenuron and chlorfluazuron, in tea samples by high-performance liquid chromatography with Fe O -hyperbranched polyester nanocomposite as the adsorbent for magnetic solid-phase extraction was developed. The magnetic nanocomposite was prepared and characterized by infrared spectroscopy, vibrating sample magnetometry, and scanning electron microscopy. The as-prepared nanocomposite was used as a sorbent for the extraction and preconcentration of pesticide residues in tea samples. The extraction and desorption conditions, including mass ratios of raw materials, amount of sorbent, pH value, extraction time, and desorption time, were investigated. Under the final conditions chosen for the analysis, good linearity was obtained for all the tested compounds, with R values of at least 0.9979. The limits of detection were determined in the range of 0.15-0.3 μg/L. The recovery obtained from the analysis of tea samples with various spiked concentrations was between 90.7 and 98.4%, with relative standard deviations (n = 4) lower than 4.1%. Furthermore, the present approach was successfully applied to the quantitative determination of residues of benzoylurea insecticides in real samples.
本工作采用 Fe O -超支化聚酯纳米复合材料作为吸附剂，通过高效液相色谱法，建立了一种测定茶叶样品中苯甲酰脲类杀虫剂（包括六氟隆、氟虫脲、伏虫隆和氯氟脲）的方法。通过红外光谱、振动样品磁强计和扫描电子显微镜对磁性纳米复合材料进行了表征。所制备的纳米复合材料可用作茶叶样品中农药残留的萃取和预浓缩的吸附剂。考察了萃取和洗脱条件，包括原料的质量比、吸附剂的用量、pH 值、萃取时间和洗脱时间。在所选择的分析条件下，所有测试化合物均获得了良好的线性关系，相关系数至少为 0.9979。检测限范围为 0.15-0.3μg/L。用不同浓度添加的茶叶样品进行分析，回收率在 90.7%至 98.4%之间，相对标准偏差（n=4）低于 4.1%。此外，该方法成功应用于实际样品中苯甲酰脲类杀虫剂残留的定量测定。
