Cloud-Point Method of Extraction Co(II) and Determination by FAAS

A new, simple and versatile cloud-point extraction (CPE) methodology has been developed for type equation here. the separation and preconcentration of Co. The metals in the initial aqueous solution were complexed with 2-(2-benzothiazolylazo)-2-p-cresol (BTAC) and Triton X-114 was added as surfactant. Dilution of the surfactant-rich phase with acidified methanol was performed after phase separation, and the Co contents were measured by flame atomic absorption spectrometry. The variables affecting the cloud-point extraction were optimized using a Box-Behnken design. Under the optimum experimental conditions, enrichment factors of 29 and 25 were achieved for Cdmium. The accuracy of the method was evaluated and confirmed by analysis of the ICPAES. The limits of detection expressed to solid sample analysis were 0.1 mu g g(-1) (Co). The precision for 10 replicate measurements of 75 mu gL(-1) Co was 0.9. The method has been successfully applied to the analysis of water samples.