1，2-萘醌-4-磺酸钠分光光度法测定药品中赖氨酸

Spectrophotometric Determination of Lysine in Drugs with 1,2-Naphthoquinone-4-Sulfonate as Colour Reagent

赖氨酸与1，2-萘醌-4-磺酸钠在pH9．6的缓冲溶液中，通过亲核取代反应生成物质的量比为1：2的橙红色产物，最大吸收波长为474nm，表观摩尔吸光率为5．1×10^3L·mol^-1·cm^-1。赖氨酸的质量浓度在0．2～55mg·L^-1范围内与吸光度呈线性关系，其检出限（3s／k）为0．16mg·L^-1。应用所提出的方法测定了药物样品中赖氨酸的含量，并以此样品为基体加入赖氨酸标准溶液做回收试验，测得回收率在99．0％～100．3％之间，测定值的相对标准偏差（n=5）均小于0．55％。

In a borate buffer of pH 9. 6, based on the nucleophilic substitution reaction between lysine and sodium 1,2-naphtoquinone-4-sulfonate, a salmon pink colored compound with mole ratio of 1 to 2 was formed. The absorption maximum of this colored compound was found at the wavelength of 474 nm, and the absorption absorptivity （ε474） found was 5.1×10^3L·mol^-1·cm^-1. Linear relationship between values of absorbance and concentration of lysine was kept in the range of 0. 2--55 mg·L^-1, with detection limit （3s/k） of 0. 16 mg·L^-1. The proposed method was applied to the determination of lysine in drug samples, and test for recovery was made by adding standard lysine solution to these samples, giving values of recovery ranged from 99. 0%- 100. 3%, and values of RSD＇s （n=5） less than 0. 55%.