Can anyone share the analytical method to determine iron content in product ammonia?
We have noticed increased iron level in our produced ammonia and not sure our analytical method is accurate or not, Current method that we use are in use for last 15 years and we are not sure about accuracy as we don’t know the source for constant values. The person who wrote this method has left the organisation.
I know that this one is old but just to round things out, all that I could suggest is from ISO 15859-11:2004, Space Systems — Fluid Characteristics, Sampling and Test Methods — Part 11: Ammonia. It doesn’t call out Fe as a standalone impurity but has a lumped parameter, Nonvolatile Residue Content. That standard specifies that the analysis identify the residue constituents by the infrared spectrometric method.
I can see by web search that iron supplement tablet are often analysed using this technique. The iron is readily dissolved in acid and then the solution is subject to IR spectrometry. I’d expect that calibration of the spectro is done using standard solutions of known Fe content.
From what I can tell, an analytic method to determine Fe content should be relatively simple to develop and achieve accurate and repeatable results.