Fluorometric determination of hydrazine and ammonia separately or in mixtures

Hydrazine and ammonia are often added to boiler water to inhibit corrosion. The reagents o-phthalaldehyde and mercaptoethanol have been found to form derivatives with hydrazine and ammonia which can be determined by fluorimetry. Because the optimum pH values for formation of the hydrazine and ammonia derivatives were different, analysis of mixtures of the two components without prior separation was possible. Simulated wet-lay-up boiler water samples containing 5-200-mug/ml levels of hydrazine and ammonia have been analysed with an average relative error of about 10%.