A comparison of chemometric methods for the flow injection simultaneous spectrophotometric determination of aniline and cyclohexylamine

Abstract

A flow injection spectrophotometric method for the simultaneous determination of aniline and cyclohexylamine using multivariate calibration methods is proposed. The method is based on the reaction of these amines with 1,2-naphthoquinone-4-sulfonate, yielding spectrophotometrically active derivatives. The data analysed with multivariate calibration methods consisted of the spectra registered in the range 290–590 nm at the maximum of the flow injection peak. Although the spectrum of each derivative was characteristic, overlapping occurred and no selective wavelengths were found. The predictive abilities of principal component regression and partial least-squares regression (PLS), non-linear PLS, locally weighted regression (LWR) and artificial neural networks were examined for the determination of aniline and cyclohexylamine in sample mixtures. The accuracy for cyclohexylamine and aniline quantifications in unknown mixtures was optimum with LWR, providing overall prediction errors of 3.4 and 5.6%, respectively.