> We reasoned that the electrostatic interaction of the Li ion with Aβ deposits would be a function of the ionization capacity of the salt, and that Li salts with reduced ionization might show reduced amyloid sequestration. To assess ionization directly, we measured the conductivity of 16 lithium salts. Inorganic Li salts, including the clinical standard lithium carbonate (Li2CO3, hereafter LiC), showed significantly elevated conductivity, indicative of increased ionization, relative to organic Li salts (P = 8 × 10−4; Fig. 5a and Extended Data Fig. 7a). Of the organic Li salts, lithium orotate (C5H3LiN2O4, hereafter LiO) showed the lowest conductance across a broad Li concentration range (Fig. 5a and Extended Data Fig. 7a) and was therefore selected for further comparison with the clinical standard LiC.

From my not-exactly-expert understanding: lithium is a teeny tiny cation, and it can form compounds on a whole spectrum from ionic to covalent-ish. The authors are observing that lithium orotate does not fully dissociate in water.