烟草中Fe、Co一阶导数分光光度法同时测定的研究

Simultaneous Determination of Iron and Cobalt in Tobacco by the First-Derivative Spectrophotometric Method

本文研究了在ｐＨ４．０时，ｍｅｓｏ－四（４－磺酸基苯基）卟啉与铁、钴同时络合显色的反应条件以及一阶导数光谱行为。此体系一阶导数的灵敏度比零阶导数灵敏度高。Ｆｅ￣（３＋）～０．１８μｇ／ｍＬ、Ｃｏ￣（２＋）０～０．２４μｇ／ｍｌ，范围内符合比耳定律；检测限为：Ｆｅ￣（３＋）＝０．４８ｎｇ／ｍＬ，Ｃｏ￣（２＋）＝０．２ｎｇ／ｍＬ。回收率为：Ｆｅ９８．５％～１００．８％，Ｃｏ９９．２％～１０１．３％。此方法用于烟草中痕量Ｆｅ、Ｃｏ测定，与ＡＡＳ值相比较，结果令人满意。

A first-derivative spectrophotometric method for the simultaneous determination of iron and cobalt is presented,which is based on the formation of colored complexes of the metallic ions with meso-tetrakis (4-sulfophenyl)porphyrin at PH 4. 0. The first-order derivative spectra give a higher sensitivity than the zero-order spectra. Beer law is obeyed in the range:0～0.18 μg/mL for Fe￣(3+)and 0～0.24 μg/mL for Co￣(2+).The detection limits for iron and cobalt are 0.48 ng/mL and 0.2 ng/mL ,respectively.The recoveries are 98.5 %～100.8 % for iron and 99. 2 %～101.3 % for cobalt. The method has been used successfully for the determination of iron and cobalt in tobacco.