The on-line coupling of high-performance liquid chromatography (HPLC) principles to high-resolution NMR spectrometers offers a powerful tool for analyzing complex chemical mixtures without the need of chemical separation ( 79JCR186 and 80AC1135) as found in natural product extracts, or to characterize drug metabolites and pharmaceutical impurities.Recommended reading: 96PROG1-29 , 96ADC315, 00BIC430, 00ENC301, and 01PHY2.