Aligned deuterochloroform in cross‐linked polystyrene as a new sample for adjusting the magic angle in HR‐MAS

A new and easily usable sample for adjusting the magic angle in a high resolution magic angle spinning (HR-MAS) probe head is a swollen polymer stick in CDCl(3) . The deuterium resonance shows a quadrupolar splitting if the rotor assembly is not at the magic angle, but a sharp singlet if the magic angle is correctly adjusted.