Proton micro-magic-angle-spinning NMR spectroscopy of nanoliter samples

We present our recent progress in the development of micro-magic-angle-spinning solenoid-based probeheads for the application in high-resolution 1H solid-state NMR of nanoliter sample volumes. The use of fused-silica capillaries as sample holders results in spectra without any 1H background signal. It is possible to obtain 1H spectra of 40–80 nl samples in a few scans. We obtained high-resolution 1H spectra employing different homonuclear decoupling sequences on powdered samples of l-alanine, the tripeptide AGG, and a single crystal of l-tyrosine·HCl. In addition, we recorded high-resolution two-dimensional proton-detected 1H–13C heteronuclear correlation spectra of [U-13C3, 15N]-l-alanine and AGG with natural abundant isotope distribution.