Magnetic chitosan/ZIF-L/KCDs granular-leaf hybrid nanocomposite for magnetic dispersive µsolid phase extraction of mycotoxins from ziziphus jujuba, nuts and grains

Abstract

In this study, a novel magnetic chitosan/zeolitic imidazolate frameworks-L/kiwi peel-derived carbon dots (MCS/ZIF-L/KCDs) granular-leaf hybrid nanocomposite was synthesized and used for magnetic dispersive µsolid-phase extraction (MD-µSPE) of aflatoxins B1, B2, G1, and G2, and the extracts were analyzed by high-performance liquid chromatography with fluorescence detection (HPLC-FLD). The sorbent was characterized using Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The influential parameters were optimized, and under optimum conditions, the developed method showed excellent analytical performance with limits of detection (LOD) of 0.002–0.003 µg kg⁻¹, limits of quantification (LOQ) of 0.007–0.009 µg kg⁻¹, and linear dynamic ranges (LDR) of 0.01–750 and 0.01–1000 µg kg⁻¹, depending on the analyte and matrix. The relative recoveries (%) of 91.0–99.4, and the intra-day (n = 6) and inter-day (5 days, n = 3) precisions at ≤3.5% and ≤3.0%, were acquired, respectively, which confirmed satisfactory capability, reproducibility, and repeatability. The proposed method presented good compliance with green analytical chemistry rules.