Magic Angle Spinning (MAS) is one of the most powerful methods used in nuclear magnetic resonance (NMR) and is the only technique that allows a high-resolution NMR spectrum to be acquired on solids, semi-solids, or a mixture thereof. There are a number of types of studies using NMR that ideally should be done at elevated pressure. However, previous attempts to develop tools and methods to conduct MAS at elevated pressure have been unsuccessful.
The rotor developed by PNNL scientists has been shown to be capable of being used in MAS experiments at pressures of 100 bar or greater. The rotor is based on a unique combination of materials and design techniques that makes it capable of operating at spin speeds of several KHz and pressures of 100 bar or more with minimal leakage. The rotor was originally developed at PNNL for studies of the efficacy of various materials as possible media for underground storage of CO2 for purposes of carbon capture. However, there are many other NMR applications where the technology would potentially be useful, including studying solid state catalysts under pressure, pharmaceutical compounds under pressure and food industry processes performed under pressure. The new rotor should be readily adaptable for use in any NMR system with MAS capability. A probe assembly has been built for the new rotor by Revolution NMR, and the rotor has been successfully demonstrated at several common NMR magnetic field strengths.
More recently, PNNL has also developed a rotor capable of operating at both high pressure and high temperature for use in MAS experiments. This new rotor can withstand experimental conditions as high as 300 degrees centigrade and pressures of up to 200 bar. The new ceramic rotor enables in-situ MAS NMR studies of reactions, materials, fluids, and gases that were previously not possible.