APPLICATION OF AN AZO COUPLING REACTION TO THE DETERMINATION OF SECONDARY ALIPHATIC-AMINES AS AZO-COMPOUNDS IN WATER AND AQUEOUS EXTRACTS FROM ELASTOMERS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

An azo coupling reaction of secondary aliphatic amines (dimethylamine, diethylamine, dipropylamine, and dibutylamine) in water-acetonitrile solutions was examined by spectrophotometry. Optimum conditions for th e formation of azo compounds with 4-nitrophenyldiazonium tetrafluorobo rate (pH, ratio between the components, and time) and for their separa tion from aqueous solutions by liquid-and solid-phase extraction were found. A procedure for determining secondary aliphatic amines as azo c ompounds by reversed-phase highperformance liquid chromatography in a gradient-elution mode with the detection limits 0.002-0.014 mg/L was d eveloped.