同步荧光法测定色氨酸

The Measurement of Tryptophane with Cynchronized Scan Fluorescent Spectroscopy

用同步荧光法测定了玉米、小麦、花粉等样品中的色氨酸.一般氨基酸分析用氨基酸分析仪和液相色谱仪,而色氨酸在酸解样品时被分解测不出.要测定色氨酸,需要重新制备样品,改变体系,比较繁杂.在多种氨基酸中仅有色氨酸、酪氨酸和苯丙氨酸有天然荧光,色氨酸的天然荧光最强,提供了直接测定的有利条件.用4N氢氧化钠碱解样品,在105℃时保温24小时,然后稀释,调pH为10.5—11之间,定容.最后用同步光谱扫描的办法测定,即激发波长和发射波长的单色器之间固定一定的波长差(Δλ=68nm),同时扫描,得到一个同步荧光光谱.其浓度和荧光强度有良好的线性关系,测定范围是0.01—0.20μg/ml.本方法弥补了在氨基酸测定中酸解样品时,色氨酸被分解测不出的不足,而且方法比较简单灵敏.

This paper describes the measurement of tryptophane with synchronized scan fluorescent spectroscopy in maize, wheat and pollen. In general, am-ino acids are determined with an amino acid analyzer or HPLC . But the tryptophane is destroyed in acidolysis. Another sample has to be prepared. It is very inconvenient. Fortunately, the tryptophane has the highest natural fluorescent intensity. It provides an advantage for direct determination of trp. The sample is treated with 4N NaOH for 24h at 105℃. The pH value is adjusted to 10.5-11.0, and the sample is diluted to volume before determining trp. with △λ68nm for synchronous scanning. The fluorescent intensity is in linear correlation with the concentration of trp. in the test range of 0.01-0.20μg/ml.