Quantitative 2H NMR spectroscopy with 1H lock extender

An inexpensive external unit that allows the use of the commercial high-resolution NMR spectrometer for 2H observation with an 1H lock system is described. The external unit does not require any tuning, is extremely easy to use, and could be a cheaper and more straightforward alternative to the more expensive 19F lock configuration. An application for the quantitative determination of the natural isotopic ratio 2H/1H of ethanol and acetic acid is reported.