双波长β修正光度法测定金属络合物特征参数研究:硒（Ⅳ）－酸性铬蓝K显色体系

DUAL WAVELENGTH BETA CORRECTION SPECTROPHOTOMETRIC DETERMINATION OF METAL CHELATE′S CHARACTERISTIC PARAMETERS:SELENIUM(Ⅳ) WITH ACID CHROME BLUE K

双波长β修正光度法测定金属络合物特征参数研究：硒（Ⅳ）－酸性铬蓝Ｋ显色体系郜洪文（淮北环境保护科学研究所安徽省淮北市２３５０００）关键词β－修正光度法特征参数硒ＡＣＢＫβ修正分析理论不同于其它双波长法［１－３］的原理，它能完全消除显色体系中过量络合剂...

The principle of β correction is the first to eliminate completely the effect of the excess of a ligand from a coloured solution to give the real absorbance of the formed chelate.By using the reaction between Se(Ⅳ) and acid chrome blue K(ACBK) at pH 8.5,the chelate′s characteristic parameters have been determined with the simpler operation and more explicit equation than that employed in other conviential methods. The results thus obtained showed that Beer′s law is followed over the range 0-2.0mg/L Se(Ⅳ),the chelate formed may be expressed by Se(ACBK) and its practical molar absorptivity is equal to 1.14×10 4 L·mol -1 cm -1 at 510nm and its instability constant to 2.31×10 -5 at pH 8.5.