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- Posts: 2
- Joined: Mon Nov 11, 2013 12:31 pm
The mobile phase is a mixture of 10 mM tetrabutylammonium hydroxide at pH 7.5 and Methanol in a proportion 75 : 25 v/v. The diluent is a solution of copper (II) nitrate 1.6 mM.
The fresh sample shows a peak of EDTA but after 40 minutes appear a new peak.
Is it possible that this peak correspond to a different protonation specie of EDTA? Is it recommended to control the pH of the sample diluent?