▎ 摘 要
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 mu g L-1 with R-2 = 0.9991, and low limits of detection (3S(b)) and quantification (10S(b)) of 0.0074 mu g L-1 and 0.025 mu g 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 mu g L-1) were in the range of 95.66-99.98%, with a relative standard deviation of less than 2.01% (n=3).