Feyns L V, Thakker K D, Reif V D, Grady L T
J Pharm Sci. 1982 Nov;71(11):1242-6. doi: 10.1002/jps.2600711115.
High-performance liquid chromatography (HPLC) in the reversed-phase mode was used for the purity analysis of three pteroylglutamic acid-type reference substances (folic acid, leucovorin calcium, and methotrexate). The influence of the pH of the mobile phase on the separation of an artificial mixture of six pteroylglutamic acid derivatives and three potential impurities was studied. Results of purity analysis of current lots of USP reference standards are reported. A better separation of methotrexate from its major impurities was achieved by using a standard buffer, rather than an ion-pairing mobile phase. A separation of methotrexate and its biologically inactive 7-isomer is reported.
采用反相高效液相色谱法（HPLC）对三种蝶酰谷氨酸类对照品（叶酸、亚叶酸钙和甲氨蝶呤）进行纯度分析。研究了流动相pH值对六种蝶酰谷氨酸衍生物和三种潜在杂质的人工混合物分离的影响。报告了现行批次美国药典对照品的纯度分析结果。使用标准缓冲液而非离子对流动相能更好地将甲氨蝶呤与其主要杂质分离。本文还报道了甲氨蝶呤及其生物活性无活性的7-异构体的分离情况。
