Graphene-like BN@SiO2 nanocomposites as efficient sorbents for solid-phase extraction of Rhodamine B and Rhodamine 6G from food samples.

A novel dendritic silicon dioxide nanocomposite coated with a highly dispersed graphene-like boron nitride nanosheet (g-BN(x)@SiO2) was in-situ synthesized and employed as a solid-phase extraction material for the Rhodamine B (RhB) and Rhodamine 6G (R6G) enrichment in food samples prior to their quantitation by HPLC. The structures and morphologies of g-BN(x)@SiO2 were characterized by XRD, FTIR, BET and TEM. The adsorption performance and mechanism were investigated and showed an enhanced maximum adsorption capacity of 625 mg/g for RhB on the nanocomposite loaded with 1% of g-BN via a fast, spontaneous process. Under optimal extraction conditions, this method showed low detection and quantification limits (2.8 μg/L for RhB, 2.1 μg/L for R6G and 9.2 μg/L for RhB, 6.9 μg/L for R6G, respectively), good repeatability (RSD% <3.7%), and satisfactory spiked recoveries of 94.8%-103.1% for RhB and R6G in real chili powder and beverage. Therefore, the g-BN(1%)@SiO2-based materials possess significant potential.