The application of the “WATERGATE” suppression technique for analyzing humic substances by nuclear magnetic resonance

An improved method for obtaining 1H nuclear magnetic resonance (NMR) spectra of humic substances is described. 1H NMR spectroscopy employing the WATERGATE method has been used to investigate the organic structure of a wide range of humic substances dissolved in aqueous media. A comparison of the WATERGATE and presaturation methods were conducted to delineate the potential of WATERGATE. The results show that the WATERGATE method presents a superior water suppression technique over presaturation, affording an overall improvement of 64% suppression of the water signal compared to the overall proton signal. The major consequence of the increased water suppression is the attainment of higher quality spectra and greater structural information.