高铁试剂离子对固相萃取光度法测定几种中草药中的铁

Study on Determination of Iron(Ⅲ) in Chinese herbs by the Ferron Ion-Pair and the Solid Phase Extraction Spectrophotometry

根据高铁试剂与铁的显色反应以及用Waters Porapak^R Sep—Pal-C18固相萃取小柱对显色配合物的高倍数富集，建立了一种测定中草药中铁的新方法。在pH=4．0的HAc-NH4Ac缓冲介质中，CTMAB作为离子对试剂，高铁试剂与铁反应生成3：1稳定配合物，该显色配合物可用C18固相萃取小柱进行富集，用乙醇（内含1％的乙酸）洗脱后用光度法测定，在乙醇相中配合物λmax=610nm，ε=8．92×10^3L／（mol·cm）。铁含量在0．05～5．0μg／ml内符合比尔定律，方法用于中草药中铁含量的测定，结果令人满意。

The color reaction of the the Ferron with Iron （III） was studied . In the medium of HAc＇--NH4Ac of pH = 4.0 buffer solution and the presence of CTMAB. The colored complex of Iron （III） and the Ferron was formed. The complex can be extracted by C18 cartridge and eluted by ethanol, and then deterrninated by spectrophotometry. The molar absorptivity of the complex is 8.92 × 10^3 L/ （mol·cm） at 610 nm. Beer＇s law is obeyed in range of 0.05- 5.0 μg/ml. This method can be applied to the determination of Iron （3） in in Chinese herbs with good results.