[Comparison of various technics for determining nitrates in soil and vegetables]. / Comparaison de différentes techniques de dosage des nitrates dans les sols et dans les végétaux.

In order to compare results obtained from various analytical techniques, nitrate determinations in soils and vegetables were made by four usual methods. These are a selective electrode, an autoanalyser with dialyser that determines nitrites following a nitrate reduction step by hydrazine sulfate, another autoanalyser that reduces nitrates with cadmium metal, and the usual DEVARDA method. Interferences and limitations of these techniques are discussed.