Simultaneous Determination Of Aluminum And Gallium By Calculation Titrimetry

Gallium and aluminum belong to the third main race, and they have the similar chemistry character. But it is difficult to determine aluminum or gallium with F^- as the titrant by traditional complex titrimetry because the titration jump doesn't exist. In this article, based on the reaction between F^- and Ga³⁺,using NaF as the titrant, the multivariate calibration titrimetry of gallium and aluminum is studied, with a fluoride ISE as the directing electrode and a Ag-AgCl electrode as the reference electrode. The job includes:(l)The concentration of Ga³⁺ is determined and the errors are basically under 3% except several sample whose concentration goes beyond that of the standard sample.(2)The concentration of Ga³⁺ and Al³⁺ are determined simultaneously by multivariate calibration titrimetry under proper condition, the results are satisfying. The errors of the determination of Al³⁺ are all under 1% but that of Ga³⁺ are a little bigger.(3)The influence of NO₃^-, pH value, Cu²⁺, Zn²⁺, Ni²⁺, Co²⁺ to the determination of Ga³⁺ is discussed. According to the results, the influence of NO₃^-and pH value is small and weak.When pH value is 4.2, the influence of Cu²⁺, Zn²⁺, Ni²⁺, Co²⁺ to the determination of Ga²⁺ is bigger than their influence when pH value is 1.5 under the same condition.(4) When pH value is 4.2,the influence of Cu²⁺, Zn²⁺, Ni²⁺, Co²⁺ to the simultaneous determination of Ga³⁺ and Al³⁺ is also not great and the influence to the determination of Ga³⁺ is a little bigger than their influence to the determination of Al³⁺.(5)The errors are discussed.(6) The virtue of the determination of Ga³⁺ by multivariate calibration titrimetry is summarized. (7) The determination of Ga³⁺ by linear calculation titrimetry is studied primarily.