Magnetic dispersive µ-solid phase extraction of aflatoxin M1 from milk samples using magnetic Co/NCHP/LDH...

A novel magnetic adsorbent composed of cobalt/nitrogen-doped carbon nanohybrid particles/ZIF-8/ZIF-67 nanoparticles/layered double hydroxides was synthesized and applied for preconcentration and determination of aflatoxin M1 in different milk samples using a magnetic dispersive µSPE approach followed by high-performance liquid chromatography-florescence detection (HPLC-FLD). The synthesized adsorbent was then characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX) techniques. The affective parameters, including pH, the adsorbent dosage, ionic strength, sample volume, and desorption conditions, were studied using a matrix-matched method. The linearity of 0.5-2000 ng Kg^-1, the detection limit of 0.14 ng Kg^-1, and the quantification limit of 0.45 ng Kg^-1 were obtained. The intra-day (n = 6) and inter-day (5 days, n = 3) precisions were acquired at ≤3.3 % and ≤3.3 %, respectively, in which the results confirmed satisfactory reproducibility and repeatability. The relative recoveries (%) of 91.0- 99.0 were obtained with RSDs (%) ≤3.1 (n = 3).