Voltammetry has shown promise as a method to estimate the concentrations of actinides in the molten LiCl-KCl used as an electrolyte in spent nuclear fuel electrorefiners. This salt typically contains several actinides in addition to many active metal fission products (rare earths, Group I & II metals). However, most of the voltammetry studies to date have focused on a single actinide or lanthanide in eutectic LiCl-KCl. This paper examines experimental and analytical techniques that can be used to estimate the concentration of a molten salt mixture containing both lanthanum (III)- and gadolinium(III)-chloride in eutectic LiCl-KCl. The aspects of the experimental procedures and setup that are unique to a multi-lanthanide mixture are briefly discussed. Experimental results from qualitative and quantitative analyses of cyclic voltammetry and open-circuit potentiometry are presented. Due to the close proximity of their standard potentials, extensive analytical work is required to estimate the concentrations. Two approaches are used in this work: peak separation and multivariate analysis. The merits of these two methods will be analyzed and discussed.

• Devin Rappleye(University of Utah, 135 S. 1460 E. Rm. 412, Salt Lake City, UT 84112, USA) Corresponding author
• Sang-Mun Jeong(Chungbuk National University, Chungdae-ro 1, Seowon-Gu, Cheongju, Chungbuk 28644, Republic of Korea)
• Mario Gonzalez(University of Utah, 135 S. 1460 E. Rm. 412, Salt Lake City, UT 84112, USA)
• Lauryn C. Hansen(University of Utah, 135 S. 1460 E. Rm. 412, Salt Lake City, UT 84112, USA)
• Michael F. Simpson(University of Utah, 135 S. 1460 E. Rm. 412, Salt Lake City, UT 84112, USA)