[Simultaneous determination of tryptophan and tyrosine in injection by artificial neural network and fluorescence spectrum method].

A new fluorescence method by artificial neural network for the simultaneous determination of tryptophan and tyrosine was developed. The determination was carried out in the KH2PO4-K2HPO4 buffer solution (pH = 7.15) and at the EX (excitation) wavelength of 224 nm. In the range of 290-400 nm, the fluorescence intensities at fourteen wavelengths were taken as characteristic parameters of the artificial neural network, and the samples were arranged by the method of equality design. The mean recoveries of tryptophan and tyrosine were 100.9% and 101.6% respectively. The RSDs of the results were 4.18% and 4.17%. The method has been applied to the determination of tryptophan and tyrosine in compound amino acid injection, and the relative errors were 4.0% and 2.6%, respectively. The results were better than those of other networks in training speed and accuracy. In conclusion, the new network spectrofluorimetry is a good choice for multicomponent resolving analysis.