Very fast magic angle spinning 1H-14N 2D solid-state NMR: Sub-micro-liter sample data collection in a few minutes

Substantial resolution and sensitivity enhancements of solid-state 1H detected 14N HMQC NMR spectra at very fast MAS rates up to 80 kHz, in a 1 mm MAS rotor, are presented. Very fast MAS enhances the 1H transverse relaxation time and efficiently decouples the 1H-14N interactions, both effects leading to resolution enhancement. The micro-coil contributes to the sensitivity increase via strong 14N rf fields and high sensitivity per unit volume. 1H-14N HMQC 2D spectra of glycine and glycyl-l-alanine at 70 kHz MAS at 11.7 T are observed in a few minutes with a sample volume of 0.8 μL.