Li Jing-feng
Department of Chemistry, Inner Mongolia Normal University, Hohhot 010022, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2003 Feb;23(1):199-200.
Under the buffer medium of HAc-NaAc of pH = 6.00, Fe(III) and 4-(5-chloro-2-pyridylazo)-1, 3-Diaminobenzene form a colored complex which can be quantitatively absorbed on the strong acid cation exchange resin, and the amount of trace Fe(III) is determined by spectrophotometry. The maximum absorption wavelength is at 540 nm, the apparent molor absorptivity is 1.35 x 10(5) L.mol-1.cm-1. The Beer's law is obeyed in the range of 0-18 micrograms.25 mL-1 for Fe(III). The proposed method has been applied to the determination of trace Fe(III) in mongolian medicine with satisfactory results.
在pH = 6.00的HAc-NaAc缓冲介质中,Fe(III)与4-(5-氯-2-吡啶偶氮)-1,3-二氨基苯形成一种有色络合物,该络合物可定量吸附在强酸性阳离子交换树脂上,采用分光光度法测定痕量Fe(III)的含量。最大吸收波长为540 nm,表观摩尔吸光率为1.35×10⁵ L·mol⁻¹·cm⁻¹。Fe(III)在0 - 18 μg·25 mL⁻¹范围内符合比尔定律。该方法已应用于蒙药中痕量Fe(III)的测定,结果令人满意。