In this work, magnetic restricted-access carbon nanotubes (M-RACNTs) were synthesized, characterized and used in the dispersive solid-phase extraction (d-SPE) of organophosphate pesticides (OPPs) from food samples (broccoli, eggplant, cauliflower, and soy milk), followed by spectrophotometric determination in a flow injection analysis system. Fe₃O₄ nanoparticles were incorporated in the multi-walled carbon nanotubes employing dimethylformamide. The dimethylformamide was used as a solvent in the incorporation process, forming the suspension of both particles.

The resulting M-CNTs were covered with an external bovine serum albumin (BSA) layer, chemically crosslinked. M-RACNTs were able to efficiently capture OPPs, excluding about 95% of the proteins from food matrices. The analyses were carried out in a flow injection analysis system (FIA), with the spectrophotometric detection (at 560 nm) of the complex formed by the reaction between OPPs, N-bromosuccinimide and rhodamine B. A fractional factorial design method was used to optimize the experimental parameters. The addition/recovery test showed results from 95.5% to 108.9%. Accuracies were checked by comparing the results obtained with the proposed and standard HPLC methods, which were in agreement. The proposed method was linear from 5 to 90 μg L⁻¹ of OPPs, with limits of detection and quantification of 0.74 and 5 μg L⁻¹ and precision of 3.67%, expressed as relative standard deviation. The pre-concentration factor was about 164 times.

在这项工作中，合成了磁性受限访问的碳纳米管（M-RACNT），对其进行了表征，并将其用于从食物样品（西兰花，茄子，菜花和菜籽）中有机磷农药（OPP）的分散固相萃取（d-SPE）。豆浆），然后在流动注射分析系统中进行分光光度测定。将Fe ₃ O ₄纳米颗粒掺入采用二甲基甲酰胺的多壁碳纳米管中。在掺入过程中将二甲基甲酰胺用作溶剂，形成两个颗粒的悬浮液。

所得的M-CNT被化学交联的外部牛血清白蛋白（BSA）层覆盖。M-RACNTs能够有效捕获OPP，从食物基质中排除约95％的蛋白质。分析是在流动注射分析系统（FIA）中进行的，通过分光光度法检测由OPP，N-溴代琥珀酰亚胺和若丹明B之间的反应形成的络合物（在560 nm）。采用分数阶乘设计方法进行了优化实验参数。添加/恢复测试显示结果为95.5％至108.9％。通过比较与拟议方法和标准HPLC方法获得的结果（一致）来检查准确性。所提出的方法在5至90μgL ^-1之间呈线性OPP的检出限和定量限为0.74和5μgL ^-1，精度为3.67％，以相对标准偏差表示。预浓缩系数约为164倍。