Gravimetric and Titrimetric Determination of Titanium, Zirconium, and Hafnium and with Cupferron

Abstract

Gravimetric and titrimetric determination of titanium, zirconium, and hafnium by precipitation with cupferron (jV-nitrosophenylhydroxylamine) in 10% sulfuric acid has been investigated. The metals can be titrated with a precision of better than 0.3% (relative) when employing amperometric equivalence point detection.The procedures are simple, subject to few interferences, and can usually be applied without any or with a minimum of preliminary treatment after sample dissolution in hydrofluoric and sulfuric acids, which are efficient solvents for the metals, and their alloys and compounds. Fluoride, phosphate, and other complexing species do not interfere.The ready titrability of suspended zirconium and hafnium phosphates indicates a rapid way of completing the analysis after separation of the metals as the phosphate from sulfuric acid-hydrogen peroxide solution.

Metal(iv) phosphates as solid acid catalysts for selective cyclodehydration of 1,n-diols

“…The metal(IV) phosphates were analyzed gravimetrically for metal ions by the cupferron method 11,12 and for phosphorus as magnesium pyrophosphate. 12 Analysis showed a metal to phosphorus ratio of 1.…”

Preparation and proton conductivity of composite ionomeric membranes obtained from gels of amorphous zirconium phosphate sulfophenylenphosphonates in organic solvents

“…The precipitate (y200 mg) was then dissolved in the minimum amount of concentrated HF and Zr(IV) determined as ZrO 2 after precipitation with cupferron. 11 In all cases the molar ratio (overall P)/Zr(IV) turned out to be 2.0 ¡ 0.05.…”

Nitrogen Adsorption on Zirconium Bis Monohydrogenphosphate with α-Type Structure

“…Phosphates analysis was made both by ion chromatography (DIONEX chromatograph) and colorimetric determinations (Beckman colorimeter) [13]. The zirconium content was obtained by gravimetry, after precipitation with cupferron [14] .…”