Li Quanmin, Zhang Tiantian
College of Chemistry and Environmental Science, Henan Normal University, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007, PR China.
Spectrochim Acta A Mol Biomol Spectrosc. 2007 Jun;67(2):360-7. doi: 10.1016/j.saa.2006.07.032. Epub 2006 Jul 29.
A rapid, simple and sensitive method for the determination of lysine (Lys) using sodium 1,2-naphthoquinone-4-sulfonate (NQS) and tetradecyl benzyl dimethyl ammonium chloride (Zeph) is presented in this paper. The method is based on the russety product formed from Lys, NQS and Zeph in a buffer solution of pH 9.60, and the stoichiometric ratio of the product is 1:2:2. Beer's law is obeyed in a range of 0.09-18 microg ml(-1) of Lys at the maximum absorption of 474 nm (epsilon(474) is 8.1 x 10(5)l mol(-1)cm(-1)). The equation of linear regression is A=0.40427+0.06112C, with a linearly correlation coefficient of 0.9972. The limit of detection is 0.07 microg ml(-1), R.S.D. 0.8%, and average recovery rate in a range of 98.9-100.1%. This paper further optimizes the determination of Lys compared with the previous methods, and the reaction mechanism is studied intensively. The proposed method has been successfully applied to the determination of Lys in pharmaceutical and biological samples. The common components as nutritional additives in pharmaceuticals and other compounds in biological samples nearly do not interfere with the proposed method.
本文介绍了一种使用1,2-萘醌-4-磺酸钠（NQS）和十四烷基苄基二甲基氯化铵（西吡氯铵）测定赖氨酸（Lys）的快速、简便且灵敏的方法。该方法基于赖氨酸、NQS和西吡氯铵在pH 9.60的缓冲溶液中形成的红褐色产物，产物的化学计量比为1:2:2。在474 nm的最大吸收波长下，赖氨酸浓度在0.09 - 18 μg ml⁻¹范围内符合比尔定律（ε(474)为8.1×10⁵ l mol⁻¹ cm⁻¹）。线性回归方程为A = 0.40427 + 0.06112C，线性相关系数为0.9972。检测限为0.07 μg ml⁻¹，相对标准偏差为0.8%，平均回收率在98.9 - 100.1%范围内。与之前的方法相比，本文进一步优化了赖氨酸的测定，并深入研究了反应机理。所提出的方法已成功应用于药物和生物样品中赖氨酸的测定。药物中作为营养添加剂的常见成分以及生物样品中的其他化合物几乎不干扰所提出的方法。
