AAS法和络合返滴定法测定明矾中钾和铝元素

AAS and Complexometric Back Titration for the Determination of Potassium and Aluminum in Alum

明矾中含有钾和铝两种元素,准确测定明矾中这两种元素对其使用有着重要的意义.同时,明矾中含有对人体有害的痕量的金属铝离子,准确测定明矾中金属铝元素对人体的危害性及降低明矾危害具有一定作用.在实验测定中对原子光谱法、干法灰化法、酸溶解法、返滴定法,以及对样品前处理的方法等进行了介绍.实验中以安徽、云南两个产地食品级明矾和中药级明矾为原料,用干法灰化法及酸溶解法对样品进行预前处理,再研究原子光谱法测定明矾中的钾元素和返滴定分析法进行测定铝元素,最后分析了两种测定方法的优缺点.

Alum contains potassium and aluminum,the accurate determination of these two elements in alum is of great significance for its use. At the same time,alum contains trace amounts of aluminum ions which are harmful to human body. It is significant to determine accurately the harmfulness of aluminum elements in alum to human body and to reduce the harmfulness of alum. The methods of atomic spectrometry,dry ashing,acid dissolution,back titration and sample pretreatment were introduced. In the experiment,food-grade alum and Chinese medicine-grade alum from Anhui and Yunnan were used as raw materials,and the samples were pretreated by dry ashing method and acid dissolution method,the determination of potassium in alum by atomic spectrometry and the determination of aluminum by back titration were studied. The advantages and disadvantages of the two methods were analyzed.