Separations coupled with NMR detection

Understanding contaminant fate requires knowledge of the mechanisms by which a compound is degraded, including the rate at which it is transformed as well as the structures of the various products produced. This need to identify and characterize contaminant-transformation products at the molecular level introduces a number of unique analytical challenges. Because of the high information content provided by nuclear magnetic resonance (NMR) spectroscopy, it is an attractive method for the study of contaminant transformation, especially when combined with analysis by mass spectrometry (MS). The versatility of high-performance liquid chromatography (HPLC)-NMR makes it a robust and efficient method for the identification of components of complex mixtures, such as those encountered in the study of environmental contaminants. The role of HPLC-NMR as a tool for environmental analyses is discussed and its utility is illustrated by examples from our work to understand the transformation of the fluoroquinolone antibiotic, ciprofloxacin. Recent technological advances to improve sensitivity, such as the coupling of sample concentration by capillary (cITP), allow NMR spectroscopy to play an increasingly important role in studies of the fate of emerging contaminants. (C) 2003 Elsevier Ltd. All rights reserved.