In a previous post it was shown how one could discriminate against broad NMR lines and emphasize sharp NMR lines by using a CPMG T2 filter. This technique has tremendous power for getting detailed information from difficult samples. Biological samples containing in-tact cells can be difficult because they contain semi-solid components with extremely short T2's and liquid components with dissolved compounds having much longer T2's. The CPMG technique was used as early as 1988 to study red blood cells.* The figure below shows 600 MHz 1H NMR data collected at uOttawa on a sample of in-tact red blood cells. The sample, obtained from centrifuged human blood, was paste-like and contained no solvent. The magnet was shimmed using proton gradient shimming and the data were collected without the deuterium lock.
Thank you to Madeleine Adam of Dr. Robert Ben's research group at uOttawa for providing the sample.
* D.L. Rabenstein, K.K. Mills and E.J. Strauss, Analytical Chemistry, 60(24), 1380 A, (1988).