建立了用1,2-萘醌-4-磺酸钠测定苯丙氨酸的方法。在pH 10．0的缓冲溶液中,苯丙氨酸与1,2-萘醌-4-磺酸钠反应形成组成比为1：1的浅红色产物,其最大吸收波长λmax=474nm,表观摩尔吸光系数ε=9．5×103 L/( mol·cm)。苯丙氨酸浓度在0．15~20 mg·L-1范围内呈良好的线性关系,线性回归方程为 A=0．011+0．0576c(mg·L-1),线性相关系数r=0．9995,平均回收率在99．0%以上,本法用于测定药物样品中苯丙氨酸的含量,结果满意。%A rapid,simple and sensitive method for the determination of phenylalanine using sodium 1,2-naphthoquine-4-sulfonate as a chromogenic reagent is established in this paper. It is based on the fact that a pink product can be formed by the reaction be-tween phenylalanine and sodium 1,2-naphthoquine-4-sulfonate in pH10. 0 buffer solution,and the stoichiometric ratio of the product is 1∶1. Beer’s law is obeyed in a range of 0. 15~20 mg·L-1 for phenylalanine at the maximum absorption of 474nm(ε=9. 5×103 L ·mol-1cm-1). The linear regression equation of the calibration curve is A=0. 011+0. 0576c(mg·L-1),with a correlation coefficient of 0. 9995. The average recovery is over 99. 0%. This proposed method has been successfully applied to the determination of phenyl-alanine with satisfactory results.
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