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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: weigewg1994 on December 21, 2009, 02:59:13 PM

Title: Nitrite Test
Post by: weigewg1994 on December 21, 2009, 02:59:13 PM

If I wanted to detect the different amounts of nitrites in samples of spinach after storage, what should i do?

I thought of soaking the spinach in water then conduct a basic nitrite test. The nitrite test would be like this:

1. Add 1M sulfuric acid to sample
2. Add iron (II) sulphate to sample
3. A brown solution should form since

2NaNO2 + 2 FeSO4 + 3 H2SO4 --> Fe2(SO4)3 + 2 NaHSO4 + 2 H2O + 2 NO

Is this correct? Since nitrites are supposed to oxidize the iron (II) into iron (III), hence the change of colour. Will there be problems with my experiment? What other nitrite tests are available?

Any advice would be much appreciated!

Title: Re: Nitrite Test
Post by: Golden_4_Life on December 22, 2009, 02:15:26 PM

Be sure to include at least three conc'n levels of pure nitrite STDs {standards} in your assay; also, you may want to use a colorimeter to quantify and differentiate the slight variance in sol'n color change as a result of the oxidation.