Simple determination of nitrate in soils by second-derivative spectroscopy.

SUMMARY A new and simple method for nitrate analysis in soil extracts and soil solution is described. The method uses the second derivative of the direct ultra-violet (UV) spectrum, available from most microprocessor-controlled spectrophotometers with a UV source. Results with the proposed method were similar to those obtained by the cadmium-reduction column and ion-chromatographic methods. The main advantages of the proposed technique are that it is simple, rapid, accurate and requires no sample pre-treatment, making it useful for routine analysis of large numbers of samples. [ABSTRACT FROM AUTHOR]