摘要
本文描述了用二阶导数荧光光度法同时测定色氨酸和酪氨酸。在 p H 7.4的条件下 ,用 2 2 1nm作为激发波长 ,记录色氨酸和酪氨酸的发射光谱 ,并进行二阶导数处理。色氨酸在 318nm处 ,酪氨酸在 2 83nm处 ,二阶导数峰高与浓度成线性关系。色氨酸工作曲线的线性回归方程为 c =0 .0 0 0 7H - 0 .0 0 4,r =0 .996 4,线性范围为 0 .0 0 4到 0 .2 0 0μg . m L- 1 。酪氨酸工作曲线的线性回归方程为 c =0 .0 0 12 H -0 .0 0 40 ,r=0 .9971。线性范围为 0 .0 0 2到 0 .2 5 0 μg· m L- 1 。实验了 p H、温度和干扰离子对测定的影响 ,测定了苹果中的色氨酸和酪氨酸的含量 ,回收率分别为 (92 .0～ 10 4.0 ) %和 (98.70～ 10 2 .0 ) % ,相对标准偏差分别为 3.5 %和 2 .8%。
A new method of second order derivative fluori me try for the simultaneous determination of tryptophan and tyrosine is described.T he measurement of emission spectra is carried out with excitation at 221 nm in a KH 2PO 4-NaOH buffer solution (pH=7.4).The second-derivative peak is at 31 8 nm and 283 nm for tryptophan and tyrosine respectively.The two amino acids can be determined directly from corresponding second order derivative signals.Linea r regression equation of the calibration graph is c= 0.000 7H—0.004, wit h a correlation coefficient of linear regression of 0.996 4 for tryptophan and c=0.001 2H—0.004 0,with a correlation coefficient of linear regressin o f 0.997 1 for tyrosine.The linear ranges of determination of tryptophan and tyr osine are from 0.004 to 0.200 μg·mL- -1 and from 0.002 to 0.025 μg ·mL- -1,respectively.Effects of pH,temperature and foreign ions on the de termination 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 standar d deviation of 3.5% and 2.8%,respectively.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2000年第3期427-430,共4页
Spectroscopy and Spectral Analysis
