Turner W R, Lenkiewicz R S
J Pharm Sci. 1976 Jan;65(1):118-21. doi: 10.1002/jps.2600650127.
Isosorbide dinitrate and two isomeric isosorbide mononitrates are shown to be polarographically reducible in aqueous sodium perchlorate or potassium chloride solution. The current, measured at -1.6 v, versus the saturated calomel electrode is proportional to the concentration of organic nitrate in the 10-100-mug/ml range. Inorganic nitrate produces no interference. However, the mononitrate isomers produce an additive response to isosorbide dinitrate and cannot be determined individually. The polarographic method is applicable to single-tablet assay for content uniformity determination, with precision and accuracy comparable to automated colorimetric analysis. Comparison is made between replicate analyses obtained polarographically and by IR and automated colorimetric analysis for six different commercially available formulations. The polarographic determination is sensitive, specific for nitrate esters, precise, requires little sample preparation, and utilizes relatively inexpensive apparatus.
已证明异山梨醇二硝酸酯和两种异构的异山梨醇单硝酸酯在高氯酸钠或氯化钾水溶液中可进行极谱还原。相对于饱和甘汞电极，在-1.6伏下测得的电流与10-100微克/毫升范围内的有机硝酸盐浓度成正比。无机硝酸盐不产生干扰。然而，单硝酸酯异构体对异山梨醇二硝酸酯产生加成响应，无法单独测定。极谱法适用于单片剂含量均匀度测定，其精密度和准确度与自动比色分析相当。对六种不同市售制剂进行了极谱法、红外光谱法和自动比色法重复分析之间的比较。极谱测定法灵敏、对硝酸酯类具有特异性、精确、所需样品前处理少且使用相对便宜的仪器。
