Magnetic dispersive micro-solid phase extraction merged with microsampling flame atomic absorption spectrometry using (Zn-Al LDH)-(PTh/ DBSNa)-Fe3O4 nanosorbent for effective trace determination of nickel(II) and cadmium(II) in food samples

In this work, Zn-Al layered double hydroxide (Zn-Al LDH) combined with polythiophene (PTH)/sodium dodecyl benzene sulfonate (DBSNa) and Fe3O4 was synthesized and used in a centrifugeless ultrasound-assisted dispersive micro solid phase extraction (UA-D-mu SPE) technique for pre-concentration and separation of Ni2+ and Cd2+ ions. The final analysis of the analytes was carried out by the micro sampling flame atomic absorption spectrometry (MS-FAAS). The influences of several effective analytical parameters, including pH value, amount of nanosorbent, sonication time, and eluent volume, on the extraction efficiency were studied by experimental design method. In the optimal conditions, the linearity ranges of 5-300 and 2.5-100 ng mL(-1) for the Ni(2+)and Cd2+ ions were attained, respectively. The limits of detection (LODs) of the method were 1.3 and 0.7 ng mL(-1) for the Ni2+ and Cd2+ ions, respectively. The proposed method demonstrated to be suitable for concurrent extraction of studied metals in various vegetable and meat samples with high accuracy and enrichment factors.