Naidong W, Hua S, Verresen K, Roets E, Hoogmartens J
Katholieke Universiteit Leuven, Laboratorium voor Farmaceutische Chemie, Leuven, Belgium.
J Pharm Biomed Anal. 1991;9(9):717-23. doi: 10.1016/0731-7085(91)80212-r.
A thin-layer chromatographic (TLC) method involving UV and fluorescence densitometry is described for the assay and purity control of metacycline. With a mobile phase dichloromethane-methanol-water (58:35:7, v/v/v) and a silica gel thin-layer, previously sprayed with 10% sodium edetate solution adjusted to pH 9.0, all the potential impurities of metacycline were well separated from the main component and from each other. Results obtained with UV densitometry (TLC-UV) and fluorescence densitometry (TLC-F) were compared with those obtained by a liquid chromatography (LC) method using a poly(styrene-divinylbenzene) stationary phase. The correlation coefficients (r) for TLC-UV and LC or TLC-F and LC were better than 0.9999. For TLC-UV the relative standard deviation (RSD) for the assay of the main component was less than 2%, for TLC-F less than 3.0% and for LC less than 1.0%.
本文描述了一种采用紫外和荧光密度测定法的薄层色谱（TLC）方法，用于测定美他环素并控制其纯度。使用二氯甲烷 - 甲醇 - 水（58:35:7，v/v/v）作为流动相，硅胶薄层预先用pH值调至9.0的10%依地酸钠溶液喷雾，美他环素的所有潜在杂质均能与主要成分以及彼此之间良好分离。将紫外密度测定法（TLC - UV）和荧光密度测定法（TLC - F）得到的结果与使用聚（苯乙烯 - 二乙烯基苯）固定相的液相色谱（LC）方法得到的结果进行比较。TLC - UV与LC或TLC - F与LC的相关系数（r）均优于0.9999。对于TLC - UV，主要成分测定的相对标准偏差（RSD）小于2%，对于TLC - F小于3.0%，对于LC小于1.0%。
