Determination of ferrous iron and total iron in glass by a colorimetric method - Report of ICG/TC2, 'Chemical durability and analysis'

Technical Committee 2 of the International Commission on Glass has been req uested to establish a reliable method for analysing iron valence states in glass. The optimised procedure is based on cold decomposition of glass samp le in an inert gas atmosphere, followed by the spectrophotometric determina tion of 1,10-phenanthroline-iron complex after complexing fluoride ions and buffering the solution to a certain pH. Twelve laboratories took part in t he collaborative investigation in which iron species in glass samples of tw o different iron contents were determined. The coefficients of variation at tained for both ferrous iron and total iron are very good.