Rashidi Nodeh Hamid, Sereshti Hassan, Gaikani Hamid, Kamboh Muhammad Afzal, Afsharsaveh Zahra
Department of Chemistry, Faculty of Science, University of Tehran, Tehran, Iran.
Department of Chemistry, Faculty of Science, University of Tehran, Tehran, Iran.
J Chromatogr A. 2017 Aug 4;1509:26-34. doi: 10.1016/j.chroma.2017.06.032. Epub 2017 Jun 13.
The new magnetic graphene based hybrid silica-N-[3-(trimethoxysilyl)propyl]ethylenediamine (MG@SiO-TMSPED) nanocomposite was synthesized via sol-gel process, and used as an effective adsorbent in magnetic solid phase extraction (MSPE) of three selected pesticides followed by gas chromatography micro-electron capture detection (GC-μECD). The adsorbent was characterized using Fourier transform-infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET), Barrett-Joyner-Halenda (BJH), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDXS) techniques. The analytical validity of the developed method was evaluated under optimized conditions and the following figures of merit were obtained: linearity, 1-20μgkg with good determination coefficients (R=0.995-0.999); limits of detection (LODs), 0.23-0.30μgkg (3×SD/m, n=3); and limits of quantitation (LOQ), 0.76-1.0μgkg (10×SD/m, n=3). The precision (RSD%) of the proposed MSPE method was studied based on intra-day (3.43-8.83%, n=3) and inter-day (6.68-8.37%, n=12) precisions. Finally, the adsorbent was applied to determination of pesticides in tomato and grape samples and good recoveries were obtained in the range from 82 to 113% (RSDs 5.1-8.1%, n=3).
通过溶胶 - 凝胶法合成了新型磁性石墨烯基杂化二氧化硅 - N - [3 -（三甲氧基甲硅烷基）丙基]乙二胺（MG@SiO - TMSPED）纳米复合材料，并将其用作三种选定农药的磁性固相萃取（MSPE）中的有效吸附剂，随后进行气相色谱 - 微电子捕获检测（GC - μECD）。使用傅里叶变换红外光谱（FT - IR）、布鲁诺尔 - 埃米特 - 泰勒（BET）、巴雷特 - 乔伊纳 - 哈伦达（BJH）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和能量色散X射线光谱（EDXS）技术对吸附剂进行了表征。在优化条件下评估了所开发方法的分析有效性，并获得了以下性能指标：线性范围为1 - 20μg/kg，测定系数良好（R = 0.995 - 0.999）；检测限（LOD）为0.23 - 0.30μg/kg（3×SD/m，n = 3）；定量限（LOQ）为0.76 - 1.0μg/kg（10×SD/m，n = 3）。基于日内精密度（3.43 - 8.83%，n = 3）和日间精密度（6.68 - 8.37%，n = 12）研究了所提出的MSPE方法的精密度（RSD%）。最后，将该吸附剂应用于番茄和葡萄样品中农药的测定，回收率良好，范围为82%至113%（RSD为5.1 - 8.1%，n = 3）。
