Silicon-29 nuclear magnetic resonance spectroscopy detection limits

We show that an unmodified, commercially available high-field (17.61T) NMR spectrometer using the DEPT pulse sequence is capable of detecting silicon-containing species down to concentrations of 150 ng/mL (150 ppb) per spin site. This is in the range given for the concentration of silicon in the blood of silicone breast implant recipients, as determined by ICP analysis, and demonstrates that, contrary to the view expressed in the literature, in theory 29Si NMR may be sufficiently sensitive to be of use in determining the nature of the silicon-containing species present. A summary of the factors affecting the detection limits in NMR spectroscopy is given.