文摘
Silicate speciation in aqueous solutions containing tetraalkylammonium hydroxide as template is examined byelectrospray mass spectrometry. A thorough study hasbeen carried out to define and optimize the conditions ofanalysis for a highly concentrated reaction solution ofinorganic species-in this case, silicate oligomers-byusing different ion source designs. The results revealspecific advantages with respect to the detected species.Condensation of monomers leads to oligomeric units thatcondense further in different reaction steps to largerspecies. Potential gas-phase reactions that can disturbcharacterization of the formed silicate species were intensively investigated and characterized. One reaction thatplays a key role is the alkoxylation of Si-OH groups thatis caused by two different reactions: first, a reaction ofmethanolate from the solvent and, second, by the involvement of the template salt, tetramethylammonium hydroxide.