DETERMINATION OF ALUMINUM CONCENTRATION IN NEWSPRINT PULP WITH A FLUORIDE-SELECTIVE ELECTRODE.

Total aluminum concentrations in newsprint pulps were quickly and conveniently determined by potentiometric titration with sodium fluoride. Statistical analysis of aluminum determinations in the concentration range 21. 6 to 124 mg/liter indicated a coefficient of variation of 0. 5 to 2. 1% with 96 to 100% detection, which is adequate for most newsprint mill applications. The presence of Fe**3** plus , Fe**2** plus , and Ca**2** plus increased the error in the determination of aluminum; however, the effects were not serious at the ion concentrations typically found in newsprint pulps.