Observation of triply charged metal ion clusters by electrospray and laserspray

Studies of the gas phase ion chemistry of triply charged metal ions, M3+ = Sc3+, Y3+, La3+, Ce3+, and Yb3+, were made by electrospray and laser spray. Triply charged ion ligand complexes, M3+(ligand)(n) were produced in the g as phase by electrospray and laser spray for the following ligands; glucose ; sucrose; raffinose; cyclodextrin; ginsenoside Rb-1; dimethyl sulfoxide (D MSO) and hexamethylphosphoramide (HMPA), The ion evaporation mechanism must be invoked to explain the transfer of more surface active ions (e.g., NH4(H2O)(n)) in solution to the gas phase, while the transfer of low surface a ctive ions (e.g., La3+(sucrose)(n)) may be explained by the charged residue model. in general, the laser spray gives stronger ion signals than electro spray for aqueous and water/methanol solutions. The laser spray is found to be more suitable for the observation of ions with larger solvation energie s (e.g., Sc3+(DMSO)(n)). These results may be due to the enrichment of the sample concentration by the selective vaporization of, the volatile solvent on the tip of the stainless steel capillary and also to the finer droplet formation caused by the laser irradiation, Copyright (C) 1999 John Wiley & Sons, Ltd.