Iron Count Test Kit
Ferric iron concentration is determined in this procedure by the oxidation of iron to the ferric state at a pH value of 1 or less. The sample is then titrated with a standard EDTA solution in the presence of a salicylic acid indicator at a pH of approximately 2.4. Hydrogen sulfide interferes with the complexing action of both the EDTA solution and the salicylic acid. The hydrogen sulfide can be removed by boiling the sample with hydrochloric acid at a pH level below 1. Results are reported as ppm Fe+3 or as epm Fe+3.