Probes 2017-08-23T22:23:25+00:00

Solution State CryoProbes

All of the spectrometers (500 MHz, 3 x 800 MHz, 2 x 900 MHz) for solution NMR applications are equipped with either 5 mm TXI/TCI Cryogenic probes. The lower temperature probes reduce the thermal noise and increase overall probe sensitivity. The higher proton sensitivity of cryogenic probes offers a four-fold signal enhancement in non-polar solvent and two-fold increase in aqueous samples compared to room temperature probe. This allows NMR experiments to be performed at very low concentrations in the ~10 micromolar range. In the TXI CryoProbe, the proton and deuterium circuits are in the cold state and in the TCI CryoProbe proton, deuterium and carbon are in the cold state. In the latter, the direct observe carbon sensitivity increases by a factor of two enabling improved performance of experiments that do not depend on proton detection. The 1.7 mm TCI MicroCryoProbe compatible with 800 MHz US2 systems has the ability to observe signal from very small volumes (30 μl). The incredibly high mass sensitivity of the probe makes it an ideal tool for applications which are sample limited. With the SampleJet the microprobe can be used in high throughput screening and metabolomics.

Spectrometer CryoProbe 2 mM Sucrose
Anomeric S/N
0.1%
Ethylbenzene S/N
0.1% CHCl3
Lineshape
500 MHz 5mm TXI 470:1 4795:1 4.3/9.9/0.53
800 MHz 5mm TXI 766:1 7602:1 4.1/5.4/0.54
800 MHz US2 #1 5mm TCI 830:1 7164:1 6.3/11.9/0.82
800 MHz US2 #2 5mm TCI 930:1 9212:1 4.8/8.5/0.75
1.7mm TCI 429:1 1958:1 12/24/1.12
900 MHz 5 mm TCI 1035:1 8863:1 8.3/14.8/0.88
900 MHz US2 5 mm TCI 956:1 9097:1 7.8/15.6/0.62

Summary of Solid State Probes

Probes Tuning Range S/N 1,2 Fields. kHz 1H/13C/15N 90% B1 homogeneity volume Lower Temperature
range 0C3, 10kHz/15kHz
spinning frequency
750MHz Wide Bore/89mm
HXY wide bore, 4mm X: 150-200
Y: 70-130
13C: 160:1
15N: 25:1
120/50/50 35-40 μl -40/-30
HFX wide bore, 4mm X: 35-225 13C: 240:1 15N: 30:1 120/50/50 35-40 μl -40/-30
HRMAS, HCND, 4mm Narrowband 1H: 250:1 900 pulse
6ms/8ms/15ms
35-40 μl n/a
900MHz Standard Bore/54mm
HCN 3.2mm Efree Narrowband 13C: 110:1
15N: 20:1
86/50/50 15-20 μl -40/-30
HCN 3.2mm Narrowband 13C: 120:1
15N: 20:1
100/55/45 15-20 μl -40/-30
HX 3.2mm X: 40-250 13C: 180:1
15N: 30:1
100/70/50 15-20 μl -40/-30
HCN 4mm Narrowband 13C: 180:1
15N: 30:1
100/50/45 35-40 μl -40/-30

1CPMAS Probes: Sensitivity is measured on fully packed natural abundance Glycine samples, 4 scans, C-H cross-polarization
2HRMAS Probes: Sensitivity is measured on 45 ml sample of 0.1% Ethylbenzene in CDCl3.
3These probes have reliably achieved the sample temperatures at the indicated spinning speeds using either a Airjet cooler or Bruker cooling unit as a source of cold gas.