A Scheme for Rapid Analysis of Enamels and Frits

Abstract

A scheme has been worked out for rapid and accurate analysis of enamels and frits. The scheme enables the determination of seventeen different constituents from a stock solution of single decomposition. The stock solution was prepared by decomposing the sample with hydrofluoric and sulphuric acids. Lead and barium were separated as sulphates prior to the determination of other constituents and then lead sulphate was separated from barium sulphate for the first time with EDTA at pH 4.3. Different aliquots were used for determination of sodium and potassium by flame photometry; cadmium and zinc by polarography and traces of iron, chromium, nickel, copper, cobalt and manganese by spectrophotometry. From another aliquot of the stock solution interfering elements were removed by mercury-cathode electrolysis and then zirconium, aluminium, calcium and magnesium were determined by complexometric methods and titanium by the spectrophotometric or polarographic method. Separate samples were decomposed for determination of silica by titrimetric potassium silico fluoride method; boron by indirect complexometric method and fluorine by lead chlorofluoride or colorimetric method. The selectivity, applicability and limitations of each method have been discussed.