Gao Linxiao, Wu Lingli, Li Quanmin
College of Chemistry and Environmental Science, Henan Normal University, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007, PR China.
Anal Chim Acta. 2008 Sep 26;626(2):174-9. doi: 10.1016/j.aca.2008.08.008. Epub 2008 Aug 22.
A novel and simple spectrophotometric method for the determination of Captopril with sodium 1,2-naphthoquinone-4-sulfonate is established in this paper. The detailed reaction mechanism is proposed and discussed. It is based on the fact that captopril can catalyze the reaction between sodium 1,2-naphthoquinone-4-sulfonate and hydroxyl ion to form 2-hydroxy-1,4-naphthoquinone in buffer solution of pH 13.00. Beer's law is obeyed in a range of 0.64-80 mugmL(-1) at the maximal absorption wavelength of 442 nm. The equation of linear regression is A=0.05815+0.00589C (mugmL(-1)), with a linear regression correlation coefficient of 0.9981. The detection limit is 0.3 mugmL(-1), R.S.D. is 0.77% and the recovery rate is in range of 96.0-103.8%. Furthermore, the method has been validated and successfully applied to the determination of captopril in pharmaceutical samples.
本文建立了一种新颖、简便的用1,2-萘醌-4-磺酸钠测定卡托普利的分光光度法。提出并讨论了详细的反应机理。该方法基于卡托普利能在pH 13.00的缓冲溶液中催化1,2-萘醌-4-磺酸钠与氢氧根离子反应生成2-羟基-1,4-萘醌这一事实。在最大吸收波长442 nm处，0.64 - 80 μg·mL⁻¹范围内符合比尔定律。线性回归方程为A = 0.05815 + 0.00589C (μg·mL⁻¹)，线性回归相关系数为0.9981。检测限为0.3 μg·mL⁻¹，相对标准偏差为0.77%，回收率在96.0 - 103.8%范围内。此外，该方法已得到验证，并成功应用于药物样品中卡托普利的测定。
