Simple Cloud Point Extraction-Spectrophotometric for the Determination for Cobalt (II) Using -3-Anilino-1-Phenylimino-Thiourea

Abstract

Cloud-point extraction (CPE) procedure was applied to enrich cobalt (II) after complexing with 3-anilino-1-phenylimino-thiourea (R.) with subsequent analysis by uv–visible spectrometry with the presence of Triton X-114 as a suitable non-ionic surfactant. The experimental conditions that would affect the CPE process have been improved such as pH, concentration for (R) and volume Triton X-114(0.6ml), equilibration temperature 45∘C and duration and finally centrifugation (rate and time)4,000 rpm,20 min. Starting from the effect of pH at (4.9), pre-concentration of sample in a 5 mL solution consists of 2.5% (v/v) Triton X-114 with 1×10-3 mol.L−1 of (R.) permitted the detection (LOD) of (0.17) μg.mL-1 of cobalt (II) and limit of quantification (LOQ) ( 0.49) μg.mL -1. A linear calibration curve was obtained within the range (0.06 -3.0) μg. mL-1 with a precision that is expressed as the relative standard deviation (RSD, n =7,6.3 μg mL-1 Co (II))