负吸光度法用于生色法的研究及痕量铁的测定

A Study on Application of Negative Absorption spectrophotometry in Add Colour Spectrophotometry and Determination of Frac Ferrum

本文对负吸光度用于有色显色剂的生色法进行了系统的研究 ,提出了能测真实吸收峰的真实吸光度对信号吸光度的正、负吸光度双波长法。该方法用于这种类型的光分析、配合物组成摩尔比测定及化学反应情况判断等领域 ,效果明显优于经典法 ,能解决后者不能解决的许多问题 ,具有理论和实用价值。在对比度分别为 1 60及 4 9nm的测Fe3+ 及Zn2 + 的实例中 ,配合物真实吸收峰波长为 5 60及 4 61nm ,真实摩尔吸光系数 (εx)为 1 70× 1 0 4 及 2 1 0× 1 0 5L .mol- 1,信号摩尔吸光系数 (εs)为 3 1 0× 1 0 4 及 2 86× 1 0 5L .mol- 1.cm- 1,相应为经典法的 1 2 6、1 98、2 2 3及 2 71倍。

This paper makes a systematic study on application of negative absorption spectrophotometry in add colour photometry about chromogenic agent by colour compound and establishes dual wavelength spectrophotometry of positive and negative absorption that can determine real and signal absorbance of real absorption peak.This method applies in the field of this type photometric analysis,molar ratio determination of composition for chelate,and judgement of situation in chemical reaction and so on,the effect clearly superior to the traditional method and it can solve many questions which the latter fails to do,so it is of value both in theory and practive.In the samples of determining Fe 3+and Zn 2+ on contrast degree of wavelength 160 and 49nm respectively,the real absorption peak wavelengths of chelat formed are 560 and 461nm,the real absorption molar absorptivity(ε r)are 1 70×104 and 2 10×105L.mol -1.cm -1,the signal molar absorptivity(ε s)are 3 10×104 and 2 86×105L.mol -1.cm -1,the dates are 1 26,1 98,2 23 and 2 71 times than traditional method do.