Wang H, Hui Q, Liu L, Sun Y, Ma L
Department of Chemistry, Shandong Teachers' University, 250014 Jinan.
Guang Pu Xue Yu Guang Pu Fen Xi. 2000 Jun;20(3):427-30.
A new method of second order derivative fluorimetry for the simultaneous determination of tryptophan and tyrosine is described. The measurement of emission spectra is carried out with excitation at 221 nm in a KH2PO4-NaOH buffer solution (pH = 7.4). The second-derivative peak is at 318 nm and 283 nm for tryptophan and tyrosine respectively. The two amino acids can be determined directly from corresponding second order derivative signals. Linear regression equation of the calibration graph is c = 0.000 7H-0.004, with a correlation coefficient of linear regression of 0.9964 for tryptophan and c = 0.001 2H-0.0040, with a correlation coefficient of linear regressin of 0.9971 for tyrosine. The linear ranges of determination of tryptophan and tyrosine are from 0.004 to 0.200 microgram.mL-1 and from 0.002 to 0.025 microgram.mL-1, respectively. Effects of pH, temperature and foreign ions on the determination of tryptophan and tyrosine have been examined. Recovery is from 92.0% to 104% for tryptophan and 98.7% to 102.0% for tyrosine, and relative standard deviation of 3.5% and 2.8%, respectively.
本文描述了一种用于同时测定色氨酸和酪氨酸的二阶导数荧光法新方法。在KH2PO4-NaOH缓冲溶液（pH = 7.4）中，以221nm激发光进行发射光谱测量。色氨酸和酪氨酸的二阶导数峰分别位于318nm和283nm处。这两种氨基酸可直接从相应的二阶导数信号中测定。色氨酸校准曲线的线性回归方程为c = 0.000 7H - 0.004，线性回归相关系数为0.9964；酪氨酸校准曲线的线性回归方程为c = 0.001 2H - 0.0040，线性回归相关系数为0.9971。色氨酸和酪氨酸的线性测定范围分别为0.004至0.200微克·mL-1和0.002至0.025微克·mL-1。考察了pH、温度和外来离子对色氨酸和酪氨酸测定的影响。色氨酸的回收率为92.0%至104%，酪氨酸的回收率为98.7%至102.0%，相对标准偏差分别为3.5%和2.8%。
