Abstract An automated method has been developed for the determination of total Kjeldahl nitrogen. Sample digests are mixed with a NaOH solution and allowed to make contact with air flowing at 1000 mL/min. The mixture enters the inlet of a heating bath maintained at 75°C. On exit, ammonia gas separates from a sparging vessel and is trapped as ammonium sulfate in a dilute H2SO4 solution. An aliquot of the acid solution is resampled and made alkaline to generate ammonia, which is measured by an ammonia sensing probe. A comparison of this procedure with AOAC method 7.025 shows that the procedure is accurate and that there is no statistically significant difference between them. This procedure introduces a new approach to eliminate the interfering species present in sample digests after Kjeldahl digestion for automated ion selective electrode measurements of ammonia. Thirty samples/h can be analyzed by this method.