Anwendung einer Ammoniak‐gassensitiven Elektrode zur Ammonium‐Stickstoffbestimmung in organischen Düngern

A gas‐sensitive electrode for the determination of ammonia was tested on the basis of potentiometry by means of parts of measuring devices from the CMEA region. Samples of water, cattle slurry, pig slurry and silo seepage water in the range of concentrations of 10−5 … 10−1 mol/1 NH4‐N can be measured. Before measurement the samples have to get pH 11 and have to be diluted, if necessary. A maximum period of time of about eight minutes is required for attaining the potential constancy. The relative standard deviation varies between 0.1 and 4.79%; the rate of retrieval was 99.1% on an average. The results of the potentiometric measurements were equivalent to those of the acidimetric measuring method. The practical advantages consist in a low expenditure of material, energy and time.