DIN 51087-1
DIN 51087-1 Testing of oxidic raw and finished materials - Part 1: Spectrophotometric determination of iron(II) and iron(III) using o-phenanthroline
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 06/01/2005
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 06/01/2005