A new parallel coil MMR probe is described which can detect simultaneously the signals arising from four individual samples. The signals are differentiated using field gradients and analyzed in software yielding either a table of peaks assigned to each sample or individual spectra. When suitably developed, this method should be useful for increasing the throughput of NMR measurements, an important issue in applications such as process monitoring or the screening of large molecular libraries using NMR detection. (C) 1999 Elsevier Science B.V. All rights reserved.