ISO 3199:1975

Not applicable to the analysis of mixtures for agricultural use such as herbicides or pesticides. Indicates the risk in handling with clorates. Dissolution of the test portion in water and reduction by a known quantity, in access, of an iron(II) salt in a sulphuric acid and orthophosphoric acid medium. Titration of the excess iron(II) salt with a standard volumetric solution of potassium dichromate in the presence of barium diphenylamine-4-sulphonate solution as indicator.