紫甘蓝色素在酸碱滴定中的应用研究

Research on Application of Purple Cabbage Pigment to Acid-Base Titration

探讨了紫甘蓝色素用作酸碱指示剂进行酸碱滴定的可行性．结果显示紫甘蓝色素能准确指示酸碱滴定的终点，其色变灵敏，重现性好，准确度高．通过加入HCl标准溶液测定废酸浓度的回收率在99．06％～101．08％之间．K^-、Na^＋、Ca^2＋、Mg^2＋等金属离子对测定无干扰，Zn^2＋、Pb^2＋、Fe^3＋、Cu^2＋等过渡金属离子对测定呈现不同程度的干扰．

The feasibility of using purple cabbage pigment as indicator for acid-base titration analysis is studied. The purple cabbage pigment can aeeuratly indicate the end point of acid-base titration with sensitive colour change, good repetition, high accuracy. Through adding standard solution of HCL to detect the concentration of spent acid, the recovery of HCL among 99.06%-101.08%. K^＋ , Na^＋ , Ca^2＋ , Mg^2＋ have no disturbance to the acid-base titration; and Zn^2＋, Fe^3-, Pb^2＋, Cu^2＋ have different extents disturbance to the acid-base titration.