Solubilities of Folic Acid and Selected Synthesized Metal Folates

Resumo

The synthesis scheme and properties of folates with compositions Li₂C₁₉H₁₇N₇O₆ ∙ 5H₂O, PbC₁₉H₁₇N₇O₆ ∙ 4H₂O, CdC₁₉H₁₇N₇O₆ · 4H₂O, and Eu₂(C₁₉H₁₇N₇O₆)₃ · 12H₂O are described. The solubility constants K_S are determined for lead(II), cadmium, europium(III) and folic acid C₁₉H₁₉N₇O₆ · 2H₂O at an ionic strength I = 0.1. The contemplations on using soluble europium(III) salts to extract folic acid from solutions at pH ~6 in the form of poorly soluble europium folate (logK_S = –24.68 ± 0.11), followed by regeneration of folic acid (by 99%) in an acidic medium, and on using folic acid or soluble sodium folate as an antidote of lead poisoning are presented.