荷移光谱法测定双氯芬酸钠含量

Spectrophotometric determination of diclofenac sodium based on charge transfer reaction

目的:建立荷移光谱法测定双氯芬酸钠(DS)的含量。方法:分别以7,7,8,8-四氰基对二次甲基苯醌(TCNQ)在丙酮介质中和氯冉酸(CL)在乙醇介质中为荷移试剂,在350～900nm 波长处扫描吸收光谱。结果:DS 与 TCNQ 形成的络合物在743nm 和842nm 有2个吸收峰,表观摩尔吸光系数分别是2.10×10~4L·mol^(-1)·cm^(-1)和3.07×10~4L·mol^(-1)·cm^(-1);与 CL形成的络合物在530nm 处有吸收峰,表观摩尔吸光系数8.77×10~2L·mol^(-1)·cm^(-1)。药物浓度分别在3～50mg·L^(-1)(TCNQ法)和15～750mg·L^(-1)(CL 法)范围内服从比尔定律,平均回收率分别为97.8%和98.6%,RSD 分别为1.4%,1.0%(n=6)。用摩尔比法和等摩尔连续变化法测得荷移络合物中 DS 与配体的摩尔比均为1:1。结论:本方法操作简便,结果准确可靠,适用于测定 DS 片中的含量。

Objective：To establish an method of charge transfer spectrophotometry for determination of diclofenac sodium base （DS）. Method：Scan absorption spectra ranging from 350 nm to 900 nm by the charge transfer reagent of 7,7,8,8 - tetracyanoquinodimethane （TCNQ） in acetone and chloranilic acid （CL） in ethanol, respectively. Resuits：The apparent molar absorptivity of TCNQ complex was 2. 10 × 10^4 L · mol^-1 · cm^-1at 743 nm,and 3.07 × 10^4 L · mo1^-1 · cm^-1at 842 at;That of CL complex was 8.77 × 10^2 L · mo1^-1 · cm^-1. Beers law obeyed in the concentration range of 3 - 50 mg · L^-1 for TCNQ method and 15 - 750 mg · L^-1 for CL method. The average recoveries were 97. 8% and 98.6%. The relative standard deviations of the two methods were 1.4% and 1.0 % （ n = 6） ,respectively. The composition of complex of DS with TCNQ or CL was 1：1. Conclusion：This method is simple, rapid and reliable for determination of DS in tablets.