Determination of aromatic amines in wastewater by capillary electrophoresis

Abstract

The possibility of aromatic amine determination using capillary electrophoresis on a «KAPEL-105M» device is studied. Due to their high toxicity, aromatic amines are rated as top- priority environmental pollutants and their content in the atmosphere and water in no way should not exceed MAC. Therefore, improvement and optimization of the instrumental methods of their determination, which can shorten the sample preparation, reduce analysis time, increase accuracy of determination, and also enable automation of analysis becomes an urgent goal of the study. A method for the separation and determination of aromatic amines (aniline, benzidine, 2-aminophenol, 1- and 2-naphthylamines, 2,6-diaminopyridine) by capillary electrophoresis on a «KAPEL-105M» device with a UV detector was developed. We have specified optimal conditions for the determination of aromatic amines (wavelength, pressure, time of sample introduction, voltage) and selected the most suitable electrolyte. The effect of the nature and concentration of the electrolyte on the determination of amines was analized. The developed method exhibited good reproducibility, accuracy, selectivity of determination, and the absence of the interfering influence of the basis of the wastewater sample. The developed method for determination of the aromatic amines was tested on model solutions and real samples of waste water, whereas the correctness of the procedure was proved in spike tests. Direct spectrophotometric detection (λ = 215 nm) revealed the following detection limits: 0.1 mg/dm3 for 1- and 2-naphthylamines, 0.5 mg/dm3 for aniline, 2-aminophenol and benzidine, and 1.0 mg/dm3 — for 2,6-diaminopyridine.