Analysis of iron content without redox?

[jeppikah]

One of the questions in my workbook asks:

In this assessment task, you will analyse the iron content of the fertiliser using a redox titration. Describe another way an analysis of iron could be performed.

I'm stuck because wouldn't trying to precipitate the iron cause other unwanted ions to precipitate as well? Assuming that it's not gravimetric, then what technique would it be and how? The closest thing I got to was using a magnet but that doesn't sound very 'chemistry-like'. 

Or am I just reading the question wrong? Maybe it's just asking for a way iron can be determine and not necessarily from the fertiliser.

[Mao]

Yes, that is good thinking, gravimetric analysis of ion content isn't very reliable.

Read ahead in your textbook, you'll find there's atomic absorption spectroscopy (AAS) which is used for analysis of all sorts of metallic ions and is very reliable.

[jeppikah]

Oh ok. Thank you