Research on a new spectrophotometric method for determinating trace amounts of fluoride

Abstract

A new spectrophotometric method for determinating trace amounts of fluoride has been introduced in this article. The principle of the method is based on the reaction of fluoride with a complex of aluminum ion and xylenol orange reagent (Al-XO). The concentration of fluoride in water is determined by measuring the red color of the Al-XO complex at 555 nm or measuring the yellow color of the XO reagent at 430 nm. The factors affecting the method for the determination of fluoride were examined. At the optimum condition, the limit of quantitation of this method is 0.08-2.1 mg/L. Based on an analysis of fluoride in the actual samples, the error of the method is less than 6%. A new point of this article is that this is the first time the type of calibration curve graph A = f (logC) in the spectrophotometric method (where: A – absorption; log - logarithm; C – concentration of fluoride) has been used in the world.