基于铁氰化钾选择性氧化间接光度法同时测定药剂中半胱氨酸和胱氨酸  

Determination of cysteine and cystine in potions based on selective oxidation reaction of potassium ferricyanide by indirect photometric method

作　　者：张爱菊 白莹 张小林 ZHANG Ai-Ju;BAI-Ying;ZHANG Xiao-lin(Gansu Medical College,Pingliang,744000,China)

机构地区：[1]甘肃医学院,甘肃平凉744000

出　　处：《化学研究与应用》2018年第3期448-451,共4页Chemical Research and Application

摘　　要：K3[Fe(CN)6]作为一种高选择性的弱氧化剂,能氧化半胱氨酸而不能氧化胱氨酸。利用半胱氨酸分子中的巯基(-SH)可将K3[Fe(CN)6]还原为K4[Fe(CN)6],K4[Fe(CN)6]与Fe Cl3反应生成在730 nm处有最大吸收的可溶性蓝色物质KFe[Fe(CN)6],通过测定蓝色物质的吸光度,可间接测定半胱氨酸的含量,从而建立了准确、快速测定半胱氨酸和胱氨酸的新方法,对反应底物、显色剂和分析途径等条件进行优化。结果表明:铁氰化钾作底物,三氯化铁作显色剂间接光度法效果更好,半胱氨酸质量浓度在0~80μmol·L-1范围内与A呈良好的线性关系,线性回归方程为A=0.0180+0.0084C(μmol·L-1),线性相关系数r=0.9999,表观摩尔吸收系数ε=0.84×104L/(mol·cm)。方法用于实际药品中半胱氨酸和胱氨酸含量测定,结果与标示量基本一致。Abstract:K3[Fe(CN)6]is a highly selective weak oxidant,cysteine can be oxidized except cystine;K3[Fe(CN)6]can be reduced to K4[Fe(CN)6]by hydrosulfuryl group(SH)in cysteine molecule,and then K4[Fe(CN)6]reacted with potassium ferricyanide FeCl3 to form blue material(KFe[Fe(CN)6])which its maximum absorption wavelength is 730 nm,the content of cysteine was indirectly by determinated the absorbance of the blue material.An accurate and fast spectrophotometric method for the determination the content of cysteine and cystine had been established,chromogenic condition was optimized for reaction substrates and chromogenic agent and analysis.The results showed that the Indirect photometry is better by potassium ferricyanide as substrates and iron trichloride as chromogenic agent effect,A good linear relationship is obtained between the absorbance and the concentration of cysteine in the range of 0~80μmol·L-1,and the equation of the linear regression is A=0.0180+0.0084C(μmol·L-1),with a linear correlation coefficient is 0.9999The molar absorbancy index is 0.84×104 L/(mol·cm)This proposed method has been applied to determine the content of cysteine and cystine in real pharmaceuticals,The determination results is satisfactory.

关 键 词：半胱氨酸 胱氨酸 光度法 铁氰化钾 

分 类 号：O657.32[理学—分析化学]