镁合金中锌含量的测定一般均采用极谱法。在化学分析方法中,有硫化锌重量法、络合滴定法、有机溶剂萃取分离法等。这些方法虽有较好的准确性,但操作都很繁琐,不适合工厂试验室的需要。自 Krbl 等提出以二甲苯酚橙作为络合滴定指示剂后,这一试剂很快就被应用到比色分析。二甲苯鼢橙在 pH5～6时与锌离子生成红紫色的络合物,籍此作锌的比色测定。关于镁合金中锌的测定,迄今未见到快速比色分析法。根据镁合金的组成情况,本文试验了二甲苯酚橙与锌的显色条件,提出了镁合金中 Determination of zinc content in magnesium alloys are generally polarographic method. In the chemical analysis methods, there are zinc sulfide weight method, complexation titration, organic solvent extraction and separation methods. Although these methods have better accuracy, but the operation is cumbersome, not suitable for the needs of the factory laboratory. Since Körbl et al. Proposed xylenol orange as a complexometric titration indicator, this reagent was quickly applied to colorimetric analysis. Xylene orange at pH5 ~ 6 and zinc ions generated purple complex, which make zinc colorimetric determination. There has been no rapid colorimetric assay so far for the determination of zinc in magnesium alloys. According to the composition of the magnesium alloy, this paper tests the conditions for the color development of xylenol orange and zinc,