IMPROVEMENT OF THE ERETIC METHOD BY DIGITAL SYNTHESIS OF THE SIGNAL AND ADDITION OF A BROADBAND ANTENNA INSIDE THE NMR PROBE

Abstract

The ERETIC method provides an electronic reference signal which can be used to determine concentrations by NMR spectroscopy. We have evaluated two improvements of the method: addition of a broadband antenna in the NMR probe and digital generation of the ERETIC signal. Five solutions of dioxane, 9.12 mM, and sodium lactate in D2O, at concentrations ranging from 4.24 mM to 43.95 mM, were used to evaluate these modifications to the method. The broadband antenna does not affect the efficiency of the method, but increases its flexibility. The digital synthesis does not modify the precision, the accuracy, or the short-term stability. However, the long-term stability is dramatically improved. The advantage of this development is that the ERETIC method can be implemented on most modern NMR spectrometers without needing any hardware modification.