Abstract Boron isotope separation by liquid chromatography using boron specific resins with N-methyl glucamine as the functional group was performed. The single-stage separation factor, S, is generally dependent on the resin in the sequence S (free base form resin) > S (F- form resin) >S (Cl- form resin) ≧S (Br- form resin) for given experimental conditions. This sequence is the same as that of the pH value expected in the resin phase and reasonably understandable by assuming in addition to the predominant four-coordinate species a three-coordinate boron species in the resin phase whose relative abundance increases with decreasing pH. Supporting evidence for three-coordinate species was obtained by 1: B NMR measurements of boric acid-glycerol and boric acid-1,3-propane-diol solutions.
Sub‐Permil Interlaboratory Consistency for Solution‐Based Boron Isotope Analyses on Marine Carbonates