METHOD FOR THE SEQUENTIAL DETERMINATION OF NITRITE AND NITRATE

摘要

The invention comprises an initial detection of NO2 - with a Griess reagent, followed by the reduction of the NO3 - to NO2 - with VC13 and subsequent detection of the NO2 - produced with the excess Griess reagent present. The detection limit is < 0.05μΜand provides high precision in the determination of NO2 - and NO3 - for samples wherein the total concentration of both compounds is lower than 30μΜ. It allows the rapid analysis of large series of samples using small volumes, reducing the quantity of the sample and Griess reagent used to half. It also allows the design of a flow injection analysis system for measuring nitrite and nitrate in the same sample and the same channel, thereby using half the quantity of the sample and Griess reagent used by traditionally employed methods.