Simultaneous spectrophotometric determination of Vitamin K"3 and 1,4-naphthoquinone after cloud point extraction by using genetic algorithm based ... [An article from: Analytica Chimica Acta]

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Description:
Cloud point extraction has been used for the preconcentration of Vitamin K"3 and 1,4-naphthoquinone, after their reaction by aniline, and later simultaneous spectrophotometric analysis by genetic algorithm-partial least squares (GA-PLS) calibration using octylphenoxypolyethoxyethanol (Triton X-114) as surfactant. The chemical variables affecting the analytical performance of the methodology were studied and optimized. Under the optimum conditions [i.e., [aniline]=0.033M, [TritonX-114]=0.22% (w/v), equilibration time 15min and cloud point 25^oC], preconcentration of 15ml of sample solution permitted the detection of 0.05 and 0.08@mgml^-^1 for Vitamin K"3 and 1,4-naphtaquinone, respectively. The predictive abilities of partial least squares regression (PLS), genetic algorithm-partial least squares regression, iterative target transformation factor analysis (ITTFA) and principal components-artificial neural networks (PC-ANN) were examined for simultaneous determination of two quinines. The GA-PLS shows superiority over other applied multivariate methods due to the wavelength selection in PLS calibration using a genetic algorithm without loss of prediction capacity, provides useful information about the chemical system.