Simultaneous flow-injection flourimetric determination of ammonia and hydrazine with a novel mode of forming pH gradients

A flow injection configuration is suggested for the simultaneous determination of ammonia and hydrazine at the μg ml^?1 level by formation of zones of different pH. The analytes react with o-phthalaldehyde and mercaptoethanol to form fluorescent derivatives at different pH values. In addition to the normal flow method, a stopped flow method is proposed to increase the ranges that can be quantified. The analysis of samples containing hydrazine and ammonia in ratios between 0.3 and 70.0 is described.