Decoration of Fe3O4@SiO2@ZnO as a high performance nanosorbent on a stir bar microextraction device for preconcentration and determination of cadmium in real water samples

Abstract

In this work, a novel, fast and simple method that so called stir bar sorptive–dispersive microextraction (SBSDµE) applied for preconcentration and determination of trace amounts of Cd (II) ions in real water samples. For this purpose, Fe3O4@SiO2@ZnO core–shell microspheres were coated on a neodymium stir bar magnetically, and dispersed in the sample solution at high stirring rate, while adsorbing Cadmium target ions. The effective factors on extraction of Cd (II) (pH, stirring rate, salt effect and extraction time) were investigated and optimized using response surface methodology (RSM) as a powerful statistical technique. Under the optimal conditions, linear dynamic range (LDR) of SBSDµE method was 1–150 ng mL−1, the intra-day and inter-day relative standard deviations (RSD%) at 80 ng mL−1 concentration level were 3.7% and 8.4% (n = 5), respectively. The limit of detection (LOD) was 0.37 ng mL−1 and the limit of quantification (LOQ) was 1.23 ng mL−1. The proposed microextraction analytical method was successfully used for determination of ultra trace amounts of cadmium in some real water samples.