原子吸收分光光度法测定草珊瑚中微量铁的含量

Determination of trace iron in Sarcandra glabra by atomic absorption spectrometry

目的以原子吸收分光光度法为基础建立测定草珊瑚中微量铁的新方法。方法用浓度为3.0μg/mL的铁测试液于2%HCl溶液的体系中,研究吸收波长、燃烧器高度、灯电流(ILamp)大小、狭缝宽度(d)、空气和乙炔的流量比对测试结果的影响。最佳的测试条件为:吸收波长为248.3nm,燃烧器高度为6.0mm,ILamp为2.0mA,狭缝宽度为0.1nm,乙炔、空气流量比为1.7/6.2。结果在最佳实验条件下,铁含量在0.0～5.0μg/mL范围内与吸光度A之间呈线性关系,即A=0.078ρFe+0.008,其中ρFe为铁标准溶液浓度(μg/mL),此方程线性相关系数r=0.9990,所建立方法的相对标准偏差为0.09%～1.15%,相对误差小于1.5%。结论此测定方法简便,结果准确、可靠,可用于其它中草药中微量铁元素的测定。

Aim To find a new method for determining trace iron in Sarcandra glabra by atomic absorption spectrometry. Method The effect of absorption wavelength, burner height, lamp current, slit width, flow ratio of acetylene to air on the test results was studied in the sample solution containing 3.0μg/mL of Fe^3＋ in 2% HCl. The optimum conditions were the wavelength 248.3 nm, the burner height 6.0 mm, ILamp =2. 0 mA, the slit width 0.1 nm, and the flow ratio of acetylene to air is 1.7/6.2. Results Under the optimum experimental conditions, there was a linear relationship between the iron content and the absorbanceA in the range of 0.0-5.0 μg/mL, that is, A =0.078ρFe ＋0. 008, in which ρFe means the concentration of iron standard solutions （μg/mL）, the linear correlation coefficient r = 0. 999 0, the relative standard deviations of the established method ranged from 0.09 % to 1.15 %, and the relative error was less than 1.5 %. Conclusion The method is simple, accurate, reliable, and can be used to determine trace iron in other Chinese herbs.