Trace determination and separation of tin (II) by floatation-spectrophotometric using kalmagyte and CTAB

A novel floatation-spectrophotometric extraction method was developed for the recovery of tin (II) from aqueous samples prior to determination by UV spectrophotometric detection. The method is based on the formation of a complex between tin (II) and kalmagyte in pH=8. The complex is floated in the interface of n-hexane and aqueous phases. After removing the aqueous phase, the floated particles are dissolved in methanol and the absorbance is measured at 637 nm. Different parameters of the floatation-spectrophotometric technique such as reagent concentration, pH, surfactant, standing time and interfering ions were studied and optimized to obtain the best extraction results with the minimum interference from other compounds. Under these conditions, the extraction of the target compound was almost complete (mean values of recovery was more than 92.6%) in a short time (6 min). The optimized method demonstrated good linearity (r2 > 0.9991) in the range of 4-350 ng/mL, sensitivity (limit of detection for tin (II), 1.7 ng/mL), accuracy (0.19–7.35%) and precision (3.66%, 4.21%). The applicability of the proposed method was demonstrated by extraction of tin(II) from different water samples.