Development of a cloud-point extraction method for spectrophotometric nano determination of silver in real samples

Abstract

A cloud-point extraction process using micellar medium has been investigated for the spectrophotometric determination of Ag(I) in real samples. The proposed method was based on the selective reaction between silver ions and an azo dye reagent, 5-(4′-chlorophenylazo)-6-hydroxypyrimidine-2,4-dione (CPAHPD), in the presence of cetyltrimethylammonium bromide (CTAB) and potassium iodide salt at pH 5.5. The optimal reaction conditions were studied and the analytical characteristics of the method were obtained. Linearity for Ag(I) concentration was obeyed in the range of 0.3–5.0 ng mL⁻¹. The molar absorptivity was calculated to be 1.55 × 10⁷ L mol⁻¹ cm⁻¹ at 666 nm, while the Sandell sensitivity value was found to be 0.007 ng cm⁻². The detection and quantification limits were 0.095 and 0.297 ng mL⁻¹, respectively. The interference effects of different anions and cations were also examined. The proposed method was successfully used to determine Ag(I) in sulphargin, radiological films, panchromatic plates, human hair, tea and water samples.