Determination of Trace Amounts of Zirconium by Flotation - Spectrophotometric Method

A sensitive and reproducible method for the flotation-spectrophotometric determination of zirconium is reported. The method is based on the complex formation zirconium and xylenol orange (XO) which is floated in the interface of aqueous phase and n-hexane by vigorous shaking. By discarding the aqueous solution and n-hexane, the adsorbed complex on to the wall of a separating funnel was dissolved in a small volume of methanol solvent and its absorbance was measured at 429 nm. The effect of different parameters such as pH, concentrations of HCl, and XO, and volume of n-hexane flotation dissolvent, standing and shaking time were studied. The calibration curve was linear in the range of 7-120 ng mL(-1) of zirconium with a correlation coefficient of 0.9991. The limit of detection (LOD) was 5.8 ng mL(-1). The relative standard deviation (RSD) for seven replicate measurements of 50 and 110 ng mL(-1) of zirconium were 4.4 and 3.0%, respectively. The method was successfully applied to the determination of zirconium in water samples.