Ultrasound-assisted dispersive magnetic solid phase extraction using toner powder for the separation and preconcentration of cobalt in water and food samples and determination by flame atomic absorption spectrometer

Abstract

In this study, ultrasound-assisted dispersive magnetic solid phase extraction using toner powder (inexpensive and accessible magnetic sorbent) combined with flame atomic absorption spectrophotometry has been developed for the analysis of cobalt (II) in water and food samples. The influence of parameters (amount of toner powder, sample pH, the concentration of the complexing agent, eluent type and volume, and adsorption time) were studied as a function of the extraction recovery. The proposed method, which has been analytically characterized under its optimum operating conditions, allows the detection of cobalt (II) in the samples with method detection limits of 0.7 μg L−1. The method repeatability, expressed as the relative standard deviation (n = 10, Co2+= 50.0 μg L−1), was 3.1%, while the preconcentration factor was 50. Cobalt(II) was determined in water samples (tap water, river water, mineral water, seawater) and food samples (cabbage and cucumber) with good recoveries (96.0–104.0%) using the proposed method.