Analytical Sciences


Abstract − Analytical Sciences, 20(12), 1701 (2004).

Simultaneous Spectrophotometric Determination of p-Benzoquinone and Chloranil after Microcrystalline Naphthalene Extraction by Using Genetic Algorithm-Based Wavelength Selection-Partial Least Squares Regression
Hamid ABDOLLAHI and Leila BAGHERI
Department of Chemistry, Institute for Advanced Studies in Basic Sciences, Zanjan 45195-159, Iran
Microcrystalline naphthalene extraction has been used for the preconcentration of p-benzoquinone and tetrachloro-p-benzoquinone (chloranil), after their reaction by aniline, and later simultaneous spectrophotometric analysis by genetic algorithm-partial least squares (GA-PLS) calibration. The chemical variables affecting the analytical performance of the methodology were studied and optimized. Under the optimum conditions i.e., [aniline] = 0.05 M and [naphthalene] = 2.2% (w/v), preconcentration of 25 ml of sample solution permitted the detection of 0.32 and 0.23 µg ml-1 for p-benzoquinone and chloranil, respectively. The predictive abilities of partial least squares regression (PLS) and genetic algorithm-partial least squares regression (GA-PLS) were examined for simultaneous determination of two quinones. The GA-PLS shows superiority over other PLS 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.