高锰酸钾-甲醛-穿心莲内酯体系的流动注射化学发光分析法

在酸性介质中,高锰酸钾能氧化穿心莲内酯发生化学发光反应,而甲醛的存在可使发光强度增强,在体系中加入表面活性剂十六烷基三甲基溴化铵可以进一步增强该体系的化学发光强度。据此建立了1种流动注射化学发光测定穿心莲内酯的新方法。方法的线性范围为5.0×10-6~2.5×10-4g.mL-1,检测限1.0×10-6g.mL-1,相对标准偏差0.9%(n=12,c=1.0×10-5g.mL-1)。样品测量通量150 h-1。该法用于药物中穿心莲内酯含量的测定,结果令人满意。同时,对高锰酸钾-甲醛-穿心莲内酯体系化学发光反应机理进行了探讨。为穿心莲内酯的快速定量测定提供了1种简便、高效的方法。

Flow Injection Chemiluminescence Determination of Andrographolide Using Potassium Permanganate and Formaldehyde System

A simple flow injection chemiluminescence procedure for the determination of andrographolide was proposed,which is based on the CL emitting reaction between andrographolide and potassium permanganate in acidic medium,greatly enhanced by formaldehyde.Cetyl trimethyl ammonium bromide can further enhance the CL signal of the system.Under the optimized experimental conditions,andrographolide could be determined in a linear range from 5.0 × 10-6 to 2.5 × 10-4 g·mL-1 with a detection limit of 1.0 × 10-6 g·mL-1.The relative standard deviation of the proposed method calculated from 12 repetitive injections of 1.0 × 10-5 g·mL-1 andrographolide was 0.9%.The sample throughput was 150 h-1.The proposed method has been satisfactorily applied to the determination of andrographolide in pharmaceutical formulations with no evidence of interference from common medicaments.In addition,the CL reaction mechanism of KMnO4-HCHO-AD system was also explored.The proposed method provided a strategy for rapid determination of andrographolide.