Simultaneous determination of trace amounts of thorium and zirconium using spectrophotometric partial least-squares calibration method

A new, attractive and applicable method, based on spectrophotometic partial least-squares procedure, was proposed for simultaneous determination of thorium and zirconium using SPADNS as a colour reagent. Absorbance measurements were made in the interval of 541-620 nm with 1.0 nm steps in buffered solutions at pH 3.5. The linear dependences were obtained in the ranges of 0.5-11.5 and 1.5-14.5 mu g.ml(-1) for Th4+ and Zr4+ ions, respectively. The limits of detection were determined 0.4 and 1.2 mu g.ml(-1) for thorium and zirconium, respectively. The standard deviation (n = 3) and recovery percentage of 10 samples in the prediction set were obtained in the range 0.22-0.38 mu g.ml(-1) and 91.3-109.2, respectively. The proposed method was used for simultaneous determination of mentioned ions in spiked real water samples and wastewater of AENTC. The satisfactory results showed that the method was applicable to the analysis of samples with similar matrix.