Optimization of 13C direct detection NMR methods

C-13-detected experiments are still limited by their inherently lower sensitivity, as compared to the equivalent H-1-detected experiments. Improving the sensitivity of C-13 detection methods remains a significant area of NMR research that may provide better means for studying large macromolecular systems by NMR. In this communication, we show that C-13-detected experiments are less sensitive to the salt concentration of the sample solution than H-1-detected experiments. In addition, acquisition can be started with anti-phase coherence, resulting in higher sensitivity due to the elimination of the final INEPT transfer step.