Estimation of nitrate and nitrogen forms of vegetables by UV-spectrophotometry after photo-oxydation.
An alternative method for the estimation of nitrate and nitrogen forms in vegetables is proposed. Nitrate can be directly estimated by UV-spectrophotometry after an extraction step with water. The other nitrogen compounds are photo-oxidized into nitrate, and then estimated by UV-spectrophotometry. An oxidative solution of sodium persulfate and a Hg-UV lamp is used. Preliminary assays were realized with vegetables like salade, spinachs, artichokes, small peas, broccolis, carrots, watercress; acceptable correlations between expected and experimental values of nitrate amounts were obtained, while the detection limit needs to be lowered. The optimization of the method is underway.
T
T
Ribeiro
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S
Depres
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G
Couteau
A
A
Pauss
D009566:Nitrates / Q000032:analysis*; D017672:Nitrogen Compounds / Q000032:analysis*; D010084:Oxidation-Reduction; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*; D014675:Vegetables / Q000737:chemistry*
D009566:Nitrates; D017672:Nitrogen Compounds