A study of vitamin A as a probe in critical micelle concentration determinations of surfactants

The effects of the heteroatom donor on the complexation of various metal ions by macrocyclic polyethers were qualitatively examined by application of the ligand exchange technique in a quadruple ion trap mass spectrometer. The metal ions, including K⁺, Cs⁺, Al⁺, Mg⁺, Cu⁺ and Ni⁺, were generated by laser desorption and allowed to react with 12-crown-4 and its nitrogen and sulfur analogs, cyclen and 1,4,7,10-tetrathiacyclododecane. The orders of gas-phase basicities were established as a comparison. The relative K⁺ and Cs⁺ binding affinities of 12-crown-4 are greatest, whereas cyclen has the highest binding affinity for all the other metal ions and also the highest gas-phase basicity.