New analytical technique for the simultaneous determination of aromatic amines in environmental samples

Abstract

A new and sensitive analytical technique has been developed for the simultaneous determination of six aromatic amines (aniline, p-nitroaniline, m-nitroaniline, o-nitroaniline, 1,3 phenylenediamine and 1, 4 phenylenediamine). It is based on the differential migration of coloured derivatives formed by the reaction of diazotized amines with orcinol on a silica gel plate. Quantitative evaluation of amine is made by visual comparison of intensities of colour by spectrophtotometry. The colour system obeyed Beer’s law in the following working range: aniline, 0.5-6.6; o-nitroaniline, 0.8-7.2; p-nitroaniline, 0.2-3.3; m-nitroaniline, 0.7-6.7; p-phenylenediamine, 0.3-4.8; and m-phenyldiamine, 0.2-3.4 ppm. The Molar absorptivity and Sandell’s sensitivity have been determined. The effect of analytical parameters on migration and analysis have been evaluated. The method is highly reproducible and has been applied to determination of amines in environmental samples.