| abstract |
A tetrafluoroborate ion removal method is provided for easily and efficiently removing tetrafluoroborate ions from a liquid sample. A contact step of bringing a compound represented by the following general formula (II) into contact with a metal ion capable of planar tetracoordinate or octahedral coordination, and a liquid sample containing tetrafluoroborate ions, Removing the precipitate containing the trapped capsule-type molecules that have captured the tetrafluoroborate ions generated by the contact from the liquid sample [R 1 , R 2 , R 4 and R 5 : hydrogen atoms , A substituted or unsubstituted aliphatic group having 1 to 30 carbon atoms, or a sulfonic acid group (not simultaneously a hydrogen atom); R 6 , R 7 : a hydrogen atom or a methyl group; A 1: at least one nitrogen atom A 5- or 6-membered heterocyclic group, which may be in the meta position]. [Selection figure] None |