Patent ID: 8742331

Claim:
A method of detecting at least one anion by ESI-MS, the method comprising: adding to a sample at least one dicationic liquid salt comprising a dicationic species corresponding in structure to Formula I: and at least one counter-anion, wherein the at least one counter-anion is OH − ; wherein: R is one or more substituents independently selected from the group consisting of alkyl, alkenyl, hydroxyl, alkoxy, carbocyclyl, carbocyclylalkyl, heterocyclyl, heterocyclylalkyl and hydroxyalkyl; m is zero, 1, 2, 3 or 4; B is a divalent fragment composed of a chain of one or more moieties selected from the group consisting of C 1 -C 20 -alkylene, C 2 -C 20 -alkenylene, C 2 -C 20 -alkynylene, (—CH 2 -carbocyclyl-CH 2 —) n , (—CH 2 -carbocyclyl-) n and polysiloxyl; wherein C 1 -C 20 -alkylene, C 2 -C 20 -alkenylene, and C 2 -C 20 -alkynylene optionally contain in the chain one or more heteroatoms selected from the group consisting of O, N, S and Si; wherein B is optionally substituted with one or more substituents selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy and halo; n is selected from the group consisting of 1 to 20, inclusive, to form a complex; and identifying the presence or non-presence of the complex formed between the at least one anion and the at least one dicationic liquid salt using ESI-MS.