Study on Separation and Enrichment of Trace Cobalt(II) using Microcrystalline Phenolphthalein Adsorption System

摘要

A new method of using adsorption microcrystalline phenolphthalein adsorption to separate and enrich trace cobalt has been developed. The effects of different parameters, such as the dosages of 1-(2-pyridylazo)-2-naphthol(PAN), phenolphthalein and various salts on the enrichment yield of Co~(2+) have been investigated. The possible enrichment mechanism of Co~(2+) was discussed. The results showed that under the optimum conditions, Co~(2+) could be quantificationally adsorbed on the surface of microcrystalline phenolphthalein in the form of the chelate precipitate of Co(II)-PAN, while Mn~(2+), Zn~(2+) and Al~(3+) could not be adsorbed at all. Therefore, Co~(2+) was completely separated from the above metal ions. A new method for separation/enrichment of trace cobalt using microcrystalline phenolphthalein adsorption system was established. The proposed method has been successfully applied to the separation of Co~(2+) in the synthetic water samles, and the enrichment yield was 94.3%～102.2%.