Nuclear magnetic resonance spectrometry cause

The components in a mixture separate in the column and exit from the column at different times (retention times). As they exit, the detector registers the event and causes the event to be recorded as a peak on the chromatogram. A wide range of detector types are available and include ultraviolet adsorption, refractive index, thermal conductivity, flame ionization, fluorescence, electrochemical, electron capture, thermal energy analyzer, nitrogen-phosphorus. Other less common detectors include infrared, mass spectrometry, nuclear magnetic resonance, atomic absorption, plasma emission. 

The rapid spread of mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy from the 1960s caused IR spectroscopy to be sidelined in many areas of analysis. NMR was much better at elucidating many fine details of molecular structure, while detection limits were lower using MS. 

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