High-performance liquid chromatography with nuclear magnetic resonance detection applied to organosilicon polymers : Part 2: Comparison with other methods

LC–NMR utilizing 1H and 29Si NMR spectroscopy is ideally suited for the analysis of silicones. It is shown that reversed phase gradient LC–NMR surpasses standard gel permeation chromatography (GPC) and diffusion ordered spectroscopy (DOSY) in the analysis of model hydride terminated polydimethylsiloxane. 1H and 29Si NMR in the stopped-flow arrangement leads to full identification of the components. Concentration gradient introduces a dependence of the 29Si shifts on solvent composition, this dependence can be substantially reduced by a proposed method of referencing. It is shown that the ADEQUATE version of powerful but insensitive 2D INADEQUATE experiment can be used for complete line assignment.