| Autor: |
Kautz, R. A., Goetzinger, W. K., Karger, B. L. |
| Zdroj: |
Journal of Combinatorial Chemistry; January 2005, Vol. 7 Issue: 1 p14-20, 7p |
| Abstrakt: |
An automated system for loading samples into a microcoil NMR probe has been developed using segmented flow analysis. This approach enhanced 2-fold the throughput of the published direct injection and flow injection methods, improved sample utilization 3-fold, and was applicable to high-field NMR facilities with long transfer lines between the sample handler and NMR magnet. Sample volumes of 2 μL (10−30 mM, ~10 μg) were drawn from a 96-well microtiter plate by a sample handler, then pumped to a 0.5-μL microcoil NMR probe as a queue of closely spaced plugs separated by an immiscible fluorocarbon fluid. Individual sample plugs were detected by their NMR signal and automatically positioned for stopped-flow data acquisition. The sample in the NMR coil could be changed within 35 s by advancing the queue. The fluorocarbon liquid wetted the wall of the Teflon transfer line, preventing the DMSO samples from contacting the capillary wall and thus reducing sample losses to below 5% after passage through the 3-m transfer line. With a wash plug of solvent between samples, sample-to-sample carryover was <1%. Significantly, the samples did not disperse into the carrier liquid during loading or during acquisitions of several days for trace analysis. For automated high-throughput analysis using a 16-second acquisition time, spectra were recorded at a rate of 1.5 min/sample and total deuterated solvent consumption was <0.5 mL ($1) per 96-well plate. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
