1,2-萘醌-4-磺酸钠分光光度法测定甘氨酸

摘要

A new method for the determination of glycine by using 1,2-naphthoquinone-4-sulfonic sodium(NQS) is established.The method is based on the pink product formed from glycine with NQS in a buffer solution of pH 10.0,and the stoichiometric ratio of the product is 1∶ 1.Beer's law is obeyed in a range of 0.4~80 mg·L-1 of glycine at the maximum absorption of 474nm(ε=2.8×103 L·mol-1cm-1).The linear regression equation of the calibration graph is A=0.01764+0.25291C,with a linear regression correlation coefficient of 0.9993.The detection limit is 0.2 μg·mL-1,R.S.D.is 0.64% and average recovery is over 99.7%.This proposed method has been successfully applied to the determination of glycine with satisfactory results.%建立了用1,2-萘醌-4-磺酸钠测定甘氨酸的新方法。研究表明：1,2-萘醌-4-磺酸钠与氨基酸在pH为10.0的缓冲溶液中反应,生成组成比为1∶1的浅红色产物,最大吸收波长λmax=474 nm,表观摩尔吸光系数ε=2.8×103L.mol-1cm-1。甘氨酸浓度在0.4～80 mg/L范围内呈良好的线性关系,线性回归方程为A=0.017 64＋0.013 34c（mg/L）,线性相关系数r=0.999 3,检测限为0.12mg/L,R.S.D为0.64﹪,平均回收率为99.7%以上。本法用于测定药物样品中甘氨酸的含量,结果满意。