偶合反应流动注射化学发光测定锆的研究

STUDY ON THE FIA-CHEMILUMINESCENCE DETERMINATION OF ZIRCONIUM(Ⅳ ) BASED ON COUPLED REACTION

基于Zr(N)置换Zr(Ⅱ)-NTA配合物中的Co(Ⅱ)和Co(Ⅲ)催化过氧化氢氧化鲁米诺产生化学发光的反应,建立了偶合反应流动注射化学发光测定锆的新方法.方法的线性范围为1×10^(-10)～1×10^(-7)g·ml^(-1).检出限为3×10^(-11)g·ml^(-1),方法用于地矿样中锆的测定.结果满意.

A new FIA-chemiluminescence (abbreviated as FIA-CL) method for the determination of Zr(Ⅳ) is reported in this paper. It is found that upon the addition of an equivalent amount of the complexing reagent nitri-lo triacetic acid (NTA). the intensity of chemiluminescence of the reaction system Co (Ⅱ)-Luminol-H2O0 is re-duced to a least value due to the complexation reaction of Co(Ⅱ) with NTA: and when a definite amount of Zr (Ⅳ) is added to this reaction system, a more stable complex will be formed between Zr(Ⅳ) and NTA. replacing an equivalent amount of Co(Ⅱ) from the complex Co(Ⅱ)-NTA. thus causing an increase of CL-intensity. Since there is a linear relationship between CL-intensity and Co(Ⅱ) concentration, the concentration of Zr(Ⅳ) can be calculated and determined indirectly. Based on this coupled reaction, a sensitive method for the determination of Zr (Ⅳ) is established. The linear relationship between CL-intensity and Zn (Ⅳ) concentration calculated holds over the range 1×10^(- )- 1×10^(- )g per ml of Zr(Ⅳ), with a detection limit of 3×10^(-11)g·ml^(-10). The precision of the determination is tested at the concentration level of 4/X/ 10^(-8)g·ml of Zr(Ⅳ) , and the RSD is found to be 2% (n = 11). The proposed method has been applied to the determination of Zr(Ⅳ) in ores with satisfactory results.