STUDY OF THE INCLUSION COMPLEXES OF AROMATIC-MOLECULES WITH CYCLODEXTRINS USING IONSPRAY MASS-SPECTROMETRY

The formation of inclusion complexes between cyclodextrins (cyclohexa- , cyclohepta-, and cyclooctamylose) and either 1-anilinonaphthalene-8- sulfonate or 2-p-toluidinylnaphthalene-6-sulfonate was investigated by ionspray mass spectrometry operated both in the positive and in the n egative ion mode. This soft ionisation technique allowed the detection of the inclusion complexes; the presence of false positives was exclu ded by increasing the voltage at the orifice which caused breakage of the electrostatic adducts and some fragmentation of the free cyclodext rin molecules, but left the inclusion complexes intact. The spectra re corded in the negative mode showed the presence of complexes formed by two cyclodextrin molecules and one aromatic molecule; such stoichiome try was not detected in the positive mode. (C) 1996 Elsevier Science L td.