提出了同步导数荧光光谱法同时测定食品中色氨酸、酪氨酸和苯丙氨酸的方法。试验表明:为排除干扰,色氨酸、酪氨酸和苯丙氨酸的特征同步导数荧光波长宜选定279,224,256 nm,波长差Δλ为55,70,25 nm条件下进行同步扫描。3种芳香族氨基酸的浓度分别在一定范围内与其导数荧光强度呈线性关系,检出限(3s/k)分别为6.3×10-9,1.6×10-8,4.0×10-7mol·L-1。方法用于蜂蜜、羊奶粉和啤酒样品中3种芳香族氨基酸的测定,回收率在92.3%~103%之间。

Synchronous derivative fluorimetry was proposed for the simultaneous determination of tryptophane, tyrosine and phenylalanine. It was found that the interferences were eliminated by setting at the synchronous derivative fluorescence characteristic wavelengths of 279 nm for the determination of tryptophane, 224 nm for tyrosine, 256 nm for phenylalanine, with wavelength differences (Δλ) of 55 nm, 70 nm and 25 nm respectively in the synchronous derivative fluorescence measurements. Linear relationships between values of derivative fluorescence intensity and concentration of the 3 amino acids were found in definite ranges, with detection limits (3s/k) of 6.3×10-9mol·L-1 for tryptophane, 1.6×10-8mol·L-1 for tyrosine and 4.0 ×10-7mol·L-1 for phenylalanine. The proposed method was applied to the determination of the 3 aromatic amino acids in samples of honey, goat milk powder and beer, giving values of recovery ranged from 92.3% to 103%.