无机阴离子对镍-4-〔(5-氯-2-吡啶)偶氮〕-1,3-二氨基苯显色反应的作用机理及应用研究

Effects of Inorganic Anions on Nickel (Ⅱ)-4-(5-Chloro-2-pyridylazo)-1,3-diaminobenzene Color Reaction and Its Application

被试的六种无机钠盐对Ni^(2-)-5-Cl-PADAB显色体系有不同程度的增敏作用,并能提高显色反应的选择性。初步探讨了无机阴离子对显色反应作用的机理。已成功地将Ni^(2-)-5-Cl-PADAB-NaBr体系用于废水中镍的测定。

The effect of six inorganic sodium salts on Ni(Ⅱ)-4-(5-chloro-2-pyridylazo)-1.3-diaminobenzene (5-C1-PADAB) color reaction was investigated. The sensitizing effect of inorganic anions on the color reaction decreased in the order: I >ClO4 >Br >NO3>Cl >F .The selectivity and stability of the color system were improved in the presence of these salts. The mechanism of salt effect on the color reaction was discussed by determining absorption spectrometry. pKa of color reagent and stable constants of complexes. The Ni(Ⅱ)-5-Cl-PADAB-NaBr color system has been successfully applied to the determination of trace amounts of nickel in waste water.