Reliability of an Ammonia Probe for Electrometric Determination of Total Ammonia Nitrogen in Fish Tanks

Abstract

The method involves an alkalization of a sample to pH 12 and subsequent measurement of liberated un-ionized ammonia with a gas-permeable membrane electrode. Total ammonia is measured directly rather than ammonium ion. Tests on different samples of water from aquaria and fish tanks showed a mean absolute difference of ±8.3% as compared with the phenolhypochlorite method in the concentration range of 0.5–5.1 mg/liter NH3-N. The lowest level of detection was 0.1 mg/liter NH3-N.