Zara, A. J.; Machado, S. S.; Bulhoes, L. 0.; Benedetti, A. V.; Rabockai, T. J. Electroanal. Chem. Interfacial Electrochem. 1987, 221, 165-174. Montenegro, M. I.; Pletcher, D. J. Nectroanal. Chem. Interfaclel E k t r o d "Three closely related problems associated with using multlvariate callbratlon methods In spectroscopy have surfaced recently. The flrst problem involves the deslre to transport a callbratlon model developed on one Instrument to a second or even multiple Instruments. Dlfferences between the prlmary and secondary Instruments whlch can occur for a varlety of reasons can lead to erroneous results, thereby prohibltlng transferring the callbration model and necessltating the tranqml d the callbratkn samples. The second problem occurs when instruments change over time (e.g. wavelength shift) for any reason. Again, using a calibration model for analysls when the Instrument responses are altered after the tlme calibration was performed is problematic. The third problem Is caused by the variation between samples from dlfferent productlon batches. The calibratkn model buitl from one batch mlght not be appilcable to another batch. Using the mathematlcs of multivariate cailbratlon, four dlfferent a p proaches to solving these two problems have been derived and tested wtlh computer simulation. The four standardlzatbn methods proceed by acquiring the spectra of a well-chosen subset of the calibration samples and then either correctlng the primary callbratlon model for use on secondary Instruments or correcting the spectra acqulred on the secondary Instrument to account for the response dlfferences. While standardizatlon does not outperform uslng the entire callbratlon set for recalibration, only a 1.2-1.6 times larger error Is obialned by standardlration In the slmuiatlons and a study of a near-infrared data set.

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The concentrations of uranium, thorium, barium, nickel, strontium and lead in the samples of the tailings and plant species collected from a uranium mill tailings repository in South China were analyzed. Then, the removal capability of a plant for a target element was assessed. It was found that Phragmites australis had the greatest removal capabilities for uranium (820 μg), thorium (103 μg) and lead (1,870 μg). Miscanthus floridulus had the greatest removal capabilities for barium (3,730 μg) and nickel (667 μg), and Parthenocissus quinquefolia had the greatest removal capability for strontium (3,920 μg). In this study, a novel coefficient, termed as phytoremediation factor (PF), was proposed, for the first time, to assess the potential of a plant to be used in phytoremediation of a target element contaminated soil. Phragmites australis has the highest PFs for uranium (16.6), thorium (8.68), barium (10.0) and lead (10.5). Miscanthus floridulus has the highest PF for Ni (25.0). Broussonetia papyrifera and Parthenocissus quinquefolia have the relatively high PFs for strontium (28.1 and 25.4, respectively). On the basis of the definition for a hyperaccumulator, only Cyperus iria and Parthenocissus quinquefolia satisfied the criteria for hyperaccumulator of uranium (36.4 μg/g) and strontium (190 μg/g), and could be the candidates for phytoremediation of uranium and strontium contaminated soils. The results show that the PF has advantage over the hyperaccumulator in reflecting the removal capabilities of a plant for a target element, and is more adequate for assessing the potential of a plant to be used in phytoremediation than conventional method.

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