Analysis of multiple samples using multiplex sample NMR: Selective excitation and chemical shift imaging approaches

Two improved approaches for the rapid analysis of multiple samples using multiplex sample NMR are described. In the first approach, frequency-selective 90 degrees radio frequency pulses and large pulsed field gradients are applied to excite and detect multiple samples in rapid succession. This method is advantageous for samples with relatively long longitudinal (T-1) relaxation times. In the second approach, chemical shift imaging is applied to acquire both the spectral and spatial information of multiple samples simultaneously. Chemical shift imaging is more time-consuming than selective excitation; however, it is advantageous for detecting samples with short Tl's and for signal averaging. Both approaches demonstrate the potential of multiplex sample NMR for carrying out high-throughput NMR detection.