V. Silvestre et al., Determination of substrate and product concentrations in lactic acid bacterial fermentations by proton NMR using the ERETIC method, ANALYT CHEM, 73(8), 2001, pp. 1862-1868
A H-1 NMR method is described for the determination of the concentration of
a chemically diverse group of metabolites over a wide concentration range
in fermentation medium. The method employs the use of the ERETIC signal, wh
ich produces a pseudo-FID acquired with the FID derived from the sample com
ponents. It is shown that this signal, once calibrated against an external
standard solution, can be used to determine accurately the concentration of
all components present in the medium. The method is rapid, reliable, and a
pplicable to a wide range of biological fluids. Problems such as the invisi
bility of certain components in the spectrum are overcome by a simple regul
ation of the pH.