氨基酸与乙酰丙酮和甲醛反应得到的产物能发出荧光,据此建立了同步荧光光谱法测定滁菊中氨基酸总量的方法.以苯丙氨酸作为测定滁菊中氨基酸总量的目标物.优化的试验条件如下:① 苯丙氨酸、谷氨酸的波长差为55 nm;② 甘氨酸和混合氨基酸的波长差为60 nm;③ 反应体系的pH为6.0;④ 反应温度为100 ℃;⑤ 反应时间为60 min;⑥ 4%甲醛溶液用量为1.5 mL;⑦ 2%乙酰丙酮溶液用量为1.25 mL.苯丙氨酸的质量浓度在5.00~50.0 mg·L-1范围内与其荧光强度呈线性关系,方法的检出限(3s/k)在0.30~0.87 mg·L-1之间.对苯丙氨酸样品连续测定10次,测定值的相对标准偏差为1.2%.用标准加入法做方法的回收试验,计算得回收率在64.7%~103%之间.

On the basis that amino acid reacts with acetyl acetone and formaldehyde to form fluorescence compounds,a synchronous fluorospectrophotometric method for determining the concentration of total amino acid in chrysanthemum of Chuzhou was established. Phenylalanine was used as a standard and the optimized conditions found were as follows:① wavelength difference of phenylalanine and glutamate is 55 nm;② wavelength difference of glycine and the mixture of glycine,glutamate and phenylalanine is 60 nm;③ pH of reaction system is 6.0;④ temperature of reaction is at 100 ℃;⑤ reaction time is 60 min;⑥ amount of 4% formaldehyde solution is 1.5 mL;⑦ amount of 2% acetylacetone solution is 1.25 mL. Linear relationship between values of fluorescence intensity and mass concentration of phenylalanine was kept in the range of 5.00-50.0 mg·L-1,with detection limits (3s/k) in the range of 0.30-0.87 mg·L-1. The method was carried out 10 times with phenylalanineand value of RSD found was 1.2%. Test for recovery was performed by standard addition method,giving recovery in the range of 64.7%-103%.