SPECTROPHOTOMETRIC DETERMINATION OF COPPER(II) IN WATERS AND SOILS USING FUCHSINE AS REAGENT.

The study was carried out to perform a simple and selective spectrophotometric determination of copper(II) in waters and soils using as reagent. The method is based on two successive chemical reactions: an oxidation of iodide ions to iodine from Cu(II) and an interaction of the liberated iodine with the organic dye fuchsine in acid media. The liberated iodine, equivalent to the analyte, forms a complex with fuchsine having an absorption maximum at λmax 560 nm. The Beer's law is obeyed in the concentration range of 0.5-6.0 mg l-1 with a linear regression 0.9995. The method's detection limit, limit of quantification and molar absorptivity are reported as follows: 0.0277 mg l-1, 0.0839 mg l-1, 5.8 × 104 l mol-1 cm-1, respectively. The proposed method is free from common interferences and has been applied for the determination of copper(II) in waters and soils samples. [ABSTRACT FROM AUTHOR]