Table 1.
Comparison of small and larger volume microcoil sample cells with and without susceptibility-matching plugs
| Cell type | *Total cell-sample volume | Volume Efficiency Enhancement | LWavg 50/0.55/0.11 % peak ht. | Sensitivityavg SNR 1% v/v H2O/D2O | |||
|---|---|---|---|---|---|---|---|
| Without Plugs | With Plugs | Without Plugs | With Plugs | Without Plugs | With Plugs | ||
| 500 nL active volume (1.0 mm OD glass capillary) | 9.5 μL | 0.8 μL | 11.9-fold | 0.8/20/25 Hz | 1.3/20/30 Hz (epoxy plug) | 658 | 660 |
| 500 nL active volume (1.0 mm OD custom ultem capillary) | 10 μL | 1.5 μL | 6.7-fold | 1.2/34/44 Hz | 1.5/38/48 Hz (epoxy plug) | 660 | 662 |
| 2 μL active volume (1.43 mm OD 1.05 mm ID glass capillary) | 35 μL | 4 μL | 8.8-fold | 0.8/28/31 Hz | 0.9/36/40 Hz (epoxy plug) | 950 | 940 |
| 20 μL active volume (2.8 mm OD, 2.4 mm ID glass capillary) | 140 μL | 24 μL | 6- fold (20–25 fold compared to 600 μL 5 mm NMR tube) | 0.8/22/36 | 0.9/23/33 Hz (ultem plug) | 3540 | 3530 |
*
Transfer line volume (2.5 μL for each of two 70 μm ID, 55 cm long transfer lines) is not considered in the table above. SNR for a 4-nucleus Nalorac 5 mm probe for 1% v/v H2O/D2O was 4000 and 7800 with and without sample spinning, respectively.