Nitrate Determination by a Modified Conway Microdiffusion Method

Abstract

Abstract The proposed modified Conway microdiffusion method provides for consecutive determinations of NH4- and NO3-N in a given aliquot of soil extract. Analyses of primary nitrate standards showed essentially complete recovery in the range of 1 to 20 ppm NO3-N (4 to 80 μg N/aliquot). Results for (NH4 + NO3)-Ν and NO3-N in soil extracts are comparable to those obtained, respectively, by macrodistillation with Devarda’s alloy and by the phenoldisulfonic acid colorimetric method. The method is rapid and suitable for routine analyses of soil extracts, the equipment is inexpensive, and no interferences are apparent.