Method to Eliminate Fluoride Interference in the Spectrophotometric Estimation of Zirconium: Application to U-Zr Alloys.

Abstract

In the estimation of Zr using the ultraviolet-visible (UV-Vis) spectrophotometric technique, fluoride interference is a decade-old unsolved problem. The process of repeated fuming with strong acids is often used to remove fluoride from the solution in order to estimate Zr using spectrophotometry analysis. For the first time, in this work, a simple use of AlCl3 is reported as a suppressing reagent to eliminate the interference of fluoride in the estimation of Zr. Xylenol orange in HCl medium is used as a complexing reagent. Linearity in the datum acquired from absorbance at 551 nm (λmax) is achieved over the concentration range 0.25-4.5 µg mL-1 of Zr with a molar absorptivity of 35<thinsp>030 L·mol-1·cm-1 and Sandell's sensitivity of 0.003 µg·cm-2. Zr is quantified in the variety of U-Zr alloys and various water samples using spectrophotometric detection with a classical univariate calibration with suppressing of fluoride interference through AlCl3. Results from this novel analytical method herein developed for the first time are compared with those achieved from gravimetric analysis.