中药煎液中游离态三价铁离子测定方法研究

目的：研究测定中药水煎液中游离态三价铁离子含量的方法。 方法：以铁离子对螺环罗丹明B肼衍生物开环显色反应的催化效应，使该试剂的乙醇溶液与中药煎液混合反应5 min，采用分光光度法在563 nm测定生成的显色产物。方法对铁离子具有很高的选择性和灵敏度。 结果：在铁离子浓度为1.68~22.4 mg·L^-1的范围内线性关系良好，重复性较高。检测下限为0.032mg·L^-1，川芎和红花煎液中游离态和总铁含量分别为17.99、107.0和63.53、378.6 ，结论：该方法操作简便，不需要分离，符合方法学验证基本要求，适用于中草药煎液中游离铁离子和总铁含量的测定。

Objective : To study the determination method for the free Fe³⁺in decoctions of traditional Chinese medicine. Methods: The method was based on the Fe³⁺-catalyzed conversion of spirolactam(nonfluorescence)of rhodamine B hydrazide derivative to ring-open amide(fluorescence).The ethanolic solution of FD1 was mixed with the decoction of TCM for 5 min,followed by spectrophotometrical measurement of the absorbance of colored ring-open amide at 563 nm.FD1 exhibited high selectivity and sensitivity over other metal ions. Results: Trace amounts of Fe³⁺(1.68-22.4 mg·L^-1)were determined with good accuracy and reproducibility;the detection limit was about 0.032 mg·L^-1.The free and total amounts of Fe³⁺in decoctions of the Ligusticum chuanxiong Hort.and Carthamus tinctorius L.were 17.99,107.0 and 63.53,378.6(] Conclusion :This method was simple and quick,calling for no separation,which was in accordance with the fundamental requirements of methodology validation,and can be used to determine the free and total amounts of Fe³⁺in decoction of traditional Chinese medicine.