Re: iron tests

	I was interested to see the posting that the iron tests are
thiocyanate based.  I had suspected as much from the colour produced,
but I think it important to note that this test _only_ works on iron
in the 3 oxidation state.  The test may be used to distinguish
between the two usual oxidation states of iron in solution.

Source: "A Textbook of Macro and Semimicro Qualitative Inorganic
Analysis",  Fourth edition, by Arthur I Vogel.

	Perhaps the test kits have a component that oxidizes the 
iron II to III, and one then measures a total.  Does anyone know?

Paul Sears      Ottawa, Canada