在分析一些合金或电镀液之类的试样时,常需采用分光光度法测定微量的铜(Ⅱ)和镍。若使用肟类试剂和偶氮类试剂,分别测定镍和铜(Ⅱ),就需准备两套不同的试剂,很不方便。若只使用一种与铜(Ⅱ)、镍都起反应的显色剂,如三苯甲烷类的铬天青S和许多2-吡啶偶氮类试剂,由于显色反应所需的pH相同或相近,两种有色物质的最大吸收峰的 In the analysis of some samples such as alloys or plating solutions, spectrophotometric determination of trace amounts of copper (II) and nickel is often required. If the use of oxime reagents and azo reagents, respectively, for the determination of nickel and copper (II), you need to prepare two different sets of reagents, very inconvenient. If only one reagent that reacts with copper (II) and nickel is used, such as triphenylmethane chrome azure S and many 2-pyridine azo reagents, since the pH required for the color reaction is the same or Similar to the maximum absorption peak of two colored substances