مقايسه ي كاركردهاي منابع انساني دانشگاه با كاركردهاي مديريت راهبردي منابع انساني

Genetic-Algorithm-Based Wavelength Selection in Spectrophotometric Simultaneous Determination of Uranium and Thorium Using Partial Least Squares Regression

A simple, novel and sensitive spectrophotometric method was described for simultaneous determination of uranium and thorium. The method is based on the complex formation of uranium and thorium with Arsenazo III at pH 3.0. All factors affecting on the sensitivity were optimized and the linear dynamic range for determination of uranium and thorium found. The simultaneous determination of uranium and thorium mixtures by using spectrophotometric methods is a difficult problem, due to spectral interferences. By multivariate calibration methods such as partial least squares (PLS), it is possible to obtain a model adjusted to the concentration values of the mixtures used in the calibration range. Genetic algorithm (GA) is a suitable method for selecting wavelengths for PLS calibration of mixtures with almost identical spectra without loss of prediction capacity using spectrophotometric. In this study, the calibration model is based on absorption spectra in the 600-760 nm range for 25 different mixtures of uranium and thorium. Calibration matrices were containing 0.10-21.00 and 0.25-18.50 µgml^-1 of uranium and thorium, respectively. The RMSEP for uranium and thorium with GA and without GA were 0.4340, 0.4580 and 1.5710, 1.0775, respectively. This procedure allows the simultaneous determination of uranium and thorium in synthetic and real matrix samples good reliability of the determination.