Can the Ultra Low Range (ULR) method for iron, method 10263, be modified to test for soluble iron?

Document ID

Document ID TE3453

Published Date

Published Date 27/05/2017
Question
Can the Ultra Low Range (ULR) method for iron, method 10263, be modified to test for soluble iron?
Summary
Modifying ULR iron method 10263 to test for soluble iron.
Answer
If only soluble iron needs to be determined, one can simply omit the heating step of method 10263. The heating step is used to dissolve the particulate iron.

The calibration is based on 15 ml of sample and 10 drops of FerroZine reagent. As long as these volumes are maintained there shouldn't be an issue.

A 5 minute reaction time should be allowed for the FerroZine reagent to reduce any ferric iron to ferrous iron which is necessary for the color reaction. At room temperature, this reaction time should not dissolve significant amounts of particulate magnetite.