Optimization of magnetic solid phase microextraction with CoFe2O4 nanoparticles unmodified for preconcentration of cadmium in environmental samples by flame atomic absorption spectrometry

DE S. DIAS, FABIO; PEDRA, PABLO P.; GUARINO, MARIA ELIZABETH P.A.; DE A. BEZERRA, MARCOS; COSTA PEREIRA, AMALIA L.; MARCHETTI, SERGIO GUSTAVO

MICROCHEMICAL JOURNAL

ELSEVIER SCIENCE BV

Año: 2019 vol. 146 p. 1095 - 1101

0026-265X

A method of preconcentration based in the magnetic solid phase microextraction with CoFe2O4 nanoparticles forthe determination of cadmium in oyster and water samples using flame atomic absorption spectrometry (FAAS).Magnetic nanomaterials ones have aroused a greater interest in the area of analytical chemistry because of thehigh area of material and separation facility of the adsorbent. The statistical significance variables, extractiontime, nanoparticles mass, pH, eluent concentration and desorption time were evaluated using a fractional factorialdesign of two levels (2). Afterward, a design Doehlert was used to optimize the pre-concentrationprocess. The best experimental conditions were: nanoparticles mass (25 mg), pH (10.0) and eluent concentrationof 1.20 mol L5?1and LOQ of0.80 μg L−1. The method allowed the determination of cadmium with a LOD of 0.24 μg L−1. The precision expressed as relative standard deviation (RSD) of 3.33% for cadmium concentrationwith 20 μg L−1, the accuracy of the method was confirmed by the analysis of materials certified reference NIST1566b Oyster tissue, pre-concentration factor 31. The method was applied to the analysis of the oyster and watersamples has determined the concentration of cadmium from 4.6 to 7.8 mg kg−1−1for oyster and 2.75 to 4.8 μg L−1for water.