Fig. 7. 2D ¹⁷O 3QMAS spectra of (a) [2-¹⁷O]-α-d-glucose and (b) [3/5/6-¹⁷O]-α-d-glucose obtained at 18.8 T with a Bruker 3.2 mm CPMAS CryoProbe. The sample spinning frequency was 15 kHz. Each sample contains 10% (w/w) Cu–EDTA. Experimental (black traces) and simulated (red traces) F2-slice spectra are displayed on the side. Data acquisition parameters are: (a), recycle delay 1 s, 48 t₁ increments (with apodization weighted sampling, n₀ = 1536 transients), total experimental time 10 h; (b) recycle delay 1 s, 32 t₁ increments (with apodization weighted sampling, n₀ = 31 680 transients), total experimental time 6 days.