Zinc ferrite as a magnetic sorbent for the dispersive micro solid-phase extraction of sulfonamides and their determination by HPLC

Abstract

In this study, the use of zinc ferrites in a magnetic, ultrasound-assisted dispersive micro solid-phase extraction procedure for the determination of sulfonamides is developed. Zinc ferrites can efficiently and selectively extract sulfonamides from environmental and food matrixes. Their synthesis is straightforward, and the resulting material exhibits favorable magnetic properties for its harvesting, after extraction. As a proof of concept, an analytical method was developed for the determination of sulfonamides in lake water and egg samples using high-performance liquid chromatography with diode array detection. The new procedure exhibits low limits of quantification (0.06 up to 0.11 μg L−1), low matrix effect (from −8% to 8%), acceptable recoveries (88–101%) and satisfactory enrichment factors (111–141). Moreover, the method has a wide linear range (up to 250 μg L−1) making it possible to determine sulfonamides at concentrations above and below the maximum residue limit. Due to the aforementioned merits, the few synthetic steps required and the efficiency of sample preparation, the developed method can be used for the routine analysis of sulfonamides. Moreover, this study highlights the affinity of zinc for sulfonamides, a property that has never reaped before in analytical chemistry.