RAPID QUANTIFICATION OF THE NITRIFICATION INHIBITOR DICYANDIAMIDE IN SOIL SAMPLES, NUTRIENT MEDIA AND BACTERIAL CELL-FREE-EXTRACTS

An analysis system based on high-performance liquid chromatography (HP LC) was developed for the quantification of dicyandiamide (DCD) presen t in different forms of aqueous solutions and cell-free extracts. This novel method is simple, rapid and sensitive with a quantification lim it as low as 0.5 ng/mu 1. Separation was carried out on an H+-cation-e xchange column using 0.025 M H2SO4 as eluent. This method overcomes pr oblems inherent to the standard colorimetric method, such as interfere nce of proteins, urea or buffers.