A new dispersive micro-solid phase extraction based on rejection property method combined with FAAS for the simultaneous determination of cobalt and copper after optimisation by Box-Behnken design
Fatemeh Salimi, Mojtaba Shamsipur, Elnaz Koosha, Majid Ramezani
Abstract
A new, fast and simple technique of dispersive micro-solid phase extraction based on rejection property (DMSPE-RP) combined with flame atomic absorption spectrometry (FAAS) for the simultaneous preconcentration and determination of trace amounts of cobalt and copper ions has been introduced. In this technique, 1-(2-pyridylazo)-2-naphthol (PAN) was used as a chelating agent and adsorbent. The experimental factors affecting the analytical performance of the method such as pH of the sample solution, the concentration of PAN and salting-out effect were evaluated and optimised using Box–Behnken design. Under the optimum conditions, the method exhibited linear dynamic ranges of 5.0–350.0 µg L−1 for cobalt and 5.0–500.0 µg L−1 for copper with the coefficients of determination higher than 0.997. The detection limits were 1.2 and 1.5 µg L−1 and the enrichment factors were 184.0 and 154.0 for cobalt and copper, respectively. The accuracy of the method was evaluated by the analysis of water-certified reference material (TMDA 53.3 water). The results indicated that the presented method is a good technique for the determination of target metal ions in natural water samples.