速差动力学分析法同时测定铬铁离子的研究

Differential Speed Spectrophotometric Determination of Fe and Cr Ions in Sewage with Xylenol Orange

速差动力学分析是利用2种性质不同的离子与显色剂反应速度不同进行测定的分析方法.目前各种废水中Fe(Ⅲ)、Cr(Ⅲ)共存的情况较为多见,测定时互有干扰.二甲酚橙与Fe^(3+)、Cr^(3+)作用形成的2种配合物具有相似的吸光特性,但生成速率有显著差异.铁与二甲酚橙在室温下反应迅速,而且随温度升高其吸光度几乎不变,而铬与二甲酚橙在室温下几乎不发生反应,加热才有明显反应.据此本文同时测定了铬、铁混合物.该方法快速简便,最低检出限0.1μg/mL,回收率95％～106％.利用本法可监测印染废水中的铬、铁离子.

The present paper contains the A-t kinetics activity that exhibits in the process of reaction of Cr(333333 ) and Fe( Ⅲ ) ions with XO and other colorants. Two complex compounds derived from the reaction of Fe ( 3333333 ) and Cr (Ⅲ ) with xylenol orange and other colorants have similar light absorbance but their speeds of reaction are obviously different while the repeatability of their A-t curves is satisfactory accordingly, a new differential speed kinetics analysis has been devel-opped, with which the bimixtrue of Fe( 333333 ) and Cr(Ⅲ ) was determined simultaneously. The result is satisfactory when it is used in the determination of sample sewage. Linearity 0-0. 25 mg/ mL, recovery 95%-106% and detection limit 0. 1μg/mL.