Magnetic solid phase extraction based on a 3D reduced graphene oxide composite coupled with spectrofluorometry was proposed to determine the presence of trace rhodamine B in chili powder and tap water. The characterization results showed that Fe₃O₄ covered the surface of the 3D reduced graphene oxide (3D-RGO) composite. The adsorption behaviour and adsorption capacity of the 3D-RGO composite were investigated. Several significant factors that affect the adsorption and desorption performance were optimized. The proposed method gave a wide linear range, from 0.025 to 150 μg L⁻¹ with R² = 0.9991, and low limits of detection (3S_b) and quantification (10S_b) of 0.0074 μg L⁻¹ and 0.025 μg L⁻¹ (n = 3), respectively. Furthermore, this method was successfully applied to determine the amount of rhodamine B in real samples, and the recoveries at three different spiked levels (0.03, 10, and 20 μg L⁻¹) were in the range of 95.66–99.98%, with a relative standard deviation of less than 2.01% (n = 3).

中文翻译：

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基于3D还原氧化石墨烯的荧光光谱和磁性固相萃取测定痕量罗丹明B。

提出了基于3D还原氧化石墨烯复合材料的荧光固相萃取结合荧光光谱法，以确定辣椒粉和自来水中痕量罗丹明B的存在。表征结果表明，Fe ₃ O ₄覆盖了3D还原氧化石墨烯（3D-RGO）复合材料的表面。研究了3D-RGO复合材料的吸附行为和吸附能力。优化了影响吸附和解吸性能的几个重要因素。所提出的方法，得到线性范围宽，从0.025至150微克大号^-1与[R ² = 0.9991，和检测的低限（3小号_b）和定量（10小号_b）分别为0.0074μgL ^-1和0.025μgL ^-1（n = 3）。此外，该方法已成功应用于实际样品中若丹明B的含量测定，三种加标水平（0.03、10和20μgL ^-1）的回收率在95.66–99.98％之间，并且相对标准偏差小于2.01％（n = 3）。