Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, PR China.
J Chromatogr A. 2022 Oct 11;1681:463476. doi: 10.1016/j.chroma.2022.463476. Epub 2022 Sep 3.
A novel mosaic structured core-shell composite, Silica@C/Ni (Sil@C/Ni), has been prepared by embedding Ni nanoparticles on the surface of silica microspheres via coordination and carbonization reduction, and was used as magnetic solid-phase extraction sorbents in combination with high performance liquid chromatography (HPLC) for the extraction and determination of four benzoylurea insecticides (BUs) in tea leaves. Based on the fact that hydrogen bonding and hydrophobic interactions exist between the material and BUs, allowing BUs on the surface of the material can achieve rapid mass transfer and improved sorption performance, satisfactory extraction recoveries have been achieved in practical sample applications. Under the optimized experimental conditions, the linear ranges were 0.5-200 µg L for diflubenzuron and triflumuron, 1.0-200 µg L for teflubenzuron and 0.8-200 µg L for flufenoxuron with the correlation coefficients R ≥ 0.9991. The method has limits of detection and limits of quantification of 0.2-0.4 µg L and 0.5-1.0 µg L, respectively. The intra-day and inter-day relative standard deviations were less than 5%. The actual sample recoveries were 76.63-95.26%. In addition, Sil@C/Ni was used repeatedly for 15 times and still showed a relatively satisfactory recovery of the four BUs. Therefore, Sil@C/Ni has a high stability and can be used as an ideal magnetic solid phase extraction sorbent for the trace enrichment of BUs in tea-leaf samples.
一种新型的镶嵌结构核壳复合材料，SiO2@C/Ni（Sil@C/Ni），通过配位和碳化还原的方法，将 Ni 纳米粒子嵌入到 SiO2 微球表面，将其作为与高效液相色谱（HPLC）结合的磁性固相萃取吸附剂，用于茶叶中四种苯甲酰脲类杀虫剂（BUs）的提取和测定。基于材料与 BUs 之间存在氢键和疏水相互作用，使 BUs 能够在材料表面上实现快速的质量转移和提高的吸附性能，在实际样品应用中实现了令人满意的提取回收率。在优化的实验条件下，对除虫脲和伏虫隆的线性范围为 0.5-200 µg L，噻嗪酮和氟虫脲的线性范围为 1.0-200 µg L，氟铃脲的线性范围为 0.8-200 µg L，相关系数 R 均大于 0.9991。该方法的检出限和定量限分别为 0.2-0.4 µg L 和 0.5-1.0 µg L。日内和日间相对标准偏差均小于 5%。实际样品的回收率为 76.63-95.26%。此外，Sil@C/Ni 重复使用了 15 次，仍然对四种 BUs 表现出相对满意的回收率。因此，Sil@C/Ni 具有较高的稳定性，可用作茶叶样品中 BUs 痕量富集的理想磁性固相萃取吸附剂。
