A Semi-Automated Method for the Determination of Ammonia in Urine using the Nessler Reaction

Species in urine which were likely to interfere with the determination of ammonia by Nesslerisation were adsorbed onto a precipitate of zinc hydroxide formed in situ in each sample. The ammonia concentrations in the subsequent supernatant solutions were measured using the Nessler method, adapted for use on a continuous flow analysis system. These measurements were made against a series of standards prepared from Analar grade ammonium chloride. The accuracy, reproducibility, and sensitivity of this adaptation were examined and were found to be within acceptable limits.