Folic acid magnetic nanoparticles have been prepared and utilized as an effective and reliable sorbent in magnetic dispersive solid phase extraction combined with dispersive liquid-liquid microextraction for the extraction of seven pesticides from different juices before their determination by gas chromatography–flame ionization detector. The sorbent is prepared through ball milling process using a proper mixture of folic acid and magnetic iron oxide. Characterization of the sorbent was done with X-ray diffraction pattern, scanning electron microscopy, and vibrating sample magnetometry. In the current study, limits of detection were in the range 0.12–0.33 μg L⁻¹. Relative standard deviations at a concentration of 40 μg L⁻¹ of each analyte were in the ranges of 2.15–5.14% for intra-day (n = 6) and 3.78–6.91% for inter-day (n = 4) precisions. Extraction recoveries and enrichment factors were obtained in the ranges of 70–88 % and 566–708, respectively. The performance of the method was evaluated by determination the selected pesticides in different samples.

叶酸磁性纳米粒子已被制备并用作磁性分散固相萃取结合分散液-液微萃取的一种有效且可靠的吸附剂，用于从不同果汁中提取七种农药，然后用气相色谱-火焰电离检测器进行测定。吸附剂是使用叶酸和磁性氧化铁的适当混合物通过球磨工艺制备的。吸附剂的表征是通过 X 射线衍射图、扫描电子显微镜和振动样品磁力测定法完成的。在当前的研究中，检测限在 0.12–0.33 μg L ^-1的范围内。浓度为 40 μg L ^{-1 时的}相对标准偏差对于日内 ( n = 6) 和 3.78–6.91% 的日间 ( n = 4) 精密度，每种分析物的 提取回收率和富集系数分别在 70-88% 和 566-708 的范围内获得。通过测定不同样品中选定的农药来评估该方法的性能。