USE OF LIQUID-CHROMATOGRAPHY NUCLEAR-MAGNETIC-RESONANCE SPECTROSCOPY FOR THE IDENTIFICATION OF IMPURITIES IN DRUG SUBSTANCES

There are many complex analytical problems in the pharmaceutical industry which require the use of more than one instrumental technique for their solution. Hyphenated techniques such as GC-MS, LC-MS and LC-NMR have been developed to help solve such problems in a time-efficient manner. The on-line combination of HPLC and NMR offers the potential for rapid collection of detailed structural information from samples in a way no other hyphenated technique can. LC-NMR, however, is an inherently insensitive technique but this paper shows that worthwhile data can be obtained on a medium-field (400 MHz) instrument.