[Comparison between PARAFAC and SWATLD based on four components simultaneous determination].

Catechol and hydroquinone are toxic substances, while tyrosine and tryptophan are luminescent substances in natural amino acids. Because of spectra overlap of the four components, it is difficult to detect quantity directly with conventional methods. A simple and reproducible method which provides simultaneous determination of catechol, hydroquinone, tyrosine and tryptophan in the same samples is presented in the present paper. The method combined excitation-emission fluorescence spectra with PARAFAC and SWATLD. At the same time, the differences between the two methods in qualitative determination and quantitative determination are compared. When PARAFAC was applied and the component number was set to 4, the obtained recoveries of hydroquinone, catechol, tyrosine and tryptophan were (101.2 +/- 2.7)%, (99.3 +/- 3.0)%, (98.7 +/- 4.5)% and (101.6 +/- 4.7)%, respectively. Meanwhile, the recoveries of the four components were (109.0 +/- 8.0)%, (91.3 +/- 11)%, (99.7 +/- 13)% and (98.1 +/- 11)% respectively with SWATLD method. The satisfactory results showed that the two methods can be used to determinate solution containing four components directly. By comparing the algorithms, PARAFAC algorithm was found to be more advantageous than SWATLD algorithm.