ISO 9681:1990 Preview
Manganese ores and concentrates -- Determination of iron content -- Flame atomic absorption spectrometric method
The method is applicable to products having an iron content between 0,2 % (m/m) and 10 % (m/m). ISO 9681 should be read in conjunction with ISO 4297. Specifies principle, reagents, apparatus, sampling and samples, procedure, and expression of results.