Three-dimensional magnetic stannic disulfide composites for the solid-phase extraction of sulfonamide antibiotics

In the present work, three-dimensional (3D) and flower-like SnS₂ materials were coated on the surface of Fe₃O₄@nSiO₂ through an in-situ growth method. The 3D architecture could avoid the accumulation and reaggregation with better stability and was beneficial for the exposure of more active sites. The prepared magnetic SnS₂ composites were used for the enrichment of sulfonamide antibiotics (SAs), and various experimental parameters affecting the extraction efficiency were investigated. The results showed the equilibrium of extraction and desorption towards target SAs could be reached within 3 min by using the Fe₃O₄@nSiO₂-SnS₂ composites. Under optimized conditions, the proposed approach possessed good linearity in the range of 0.1-200 ng·mL^-1 with correlation coefficients r² above 0.9964 and low limits of detection (LODs) from 0.025 to 0.250 ng·mL^-1 for the five target SAs. Moreover, good repeatability was obtained with the intra-day and inter-day precision in terms of relative standard deviations (RSDs) within 1.1%-10.8% and 7.4%-13.1%, and the recoveries under three spiked concentrations were between 81.8% and 119.7% with adequate accuracy. Different samples including tap water, milk and honey were collected for magnetic solid-phase extraction and determination of target SAs by using the obtained Fe₃O₄@nSiO₂-SnS₂ composites to demonstrate the utility. All the results indicated that the proposed method had great potential for effective preconcentration and determination of SAs in complex samples.