--- In analyticalchemistry@yahoogroups.com, Scott Strole
<fsstrole@y...> wrote:
> I would like to know if anyone has a procedure to determine
the "free" iron in a sample. This is the iron that is reactive, not
any iron that is in any oxide form. I have an ICP and AA. I am also
capable of titrations. Any help would be appreciated.
it is very easy to use redox titration to determine iron in presence
of its oxide.
1ST STEP:(TOTAL IRON CONTENT)
1-first dissolve your sample in 5 ml CONC HCL
2-heat to boling, then add 10 % stannous chloride drop by drop till
colorless , then add one drop excess stannous chloride.
3-dilute to 100 ml with distilled water
4-add 5 ml 10% HgCL2, stirr well till the formation of silky white
ppt.
5-add 10 ml Zimmermanns reagent
6-titrate against 0.1N KMnO4 till pink color.(EP1)

2ND STEP (IRON OXIDE ALONE)
1- dissolve the same weight of your sample in dil H2SO4
2-Titrate against 0.1N KMnO4 till pink clor(EP2)

IRON ONLY= EP1-EP2


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