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A novel application of the wavelet transform in retrieving the separate signals from overlapping chromatographic peaks and quantitative determination of the components in the overlapping chromatograms is described. The signals can be very easily separated by decomposing an overlapping chromatographic peak into localized contributions according to their frequency, and quantitative calculation can be done by studying the contributions of higher frequency. Overlapping peaks of two- and three-component mixtures were investigated by the method, and the results show excellent correlations between peak areas of the retrieved signals and the concentrations for all of the components.

The mechanism of La(3+) effect on chlorophyll (chl) of spinach in solution culture has been studied. The results show that La(3+) can obviously promote growth, increase chlorophyll contents and photosynthetic rate of spinach. La(3+) may substitute Mg(2+) for chlorophyll formation of spinach when there is no Mg(2+) in solution. La(3+) improves significantly PSII formation and enhances electron transport rate of PSII. By ICP-MS and atom absorption spectroscopy methods, it has been revealed that rare earth elements (REEs) can enter chloroplasts and increase Mg(2+)-chl contents; and REEs bind to chlorophyll and also form REE-chl. REE-chl is about 72% in total chlorophyll with La(3+) treatment and without Mg(2+)in solution. By UV-Vis, FT-IR and extended X-ray absorption fine structure spectroscopy (EXAFS) methods, it has been found that La(3+) coordinates with nitrogen of porphyrin rings with the average La-N bond length of 0.253 nm.

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