Simultaneous determination of flavor enhancers inosine 5'-monophosphate and guanosine 5'-monophosphate in food preparations by derivative spectrophotometry.

A derivative spectrophotometric method was developed for the quantitative determination of 2 flavor enhancers, inosine 5'-monophosphate (IMP) and guanosine 5'-monophosphate (GMP), in the presence of monosodium glutamate (MSG). Procedures for determining IMP and GMP singly and in binary mixtures are described. Overlapping absorption spectra of both compounds were resolved by using first-derivative spectrophotometry. By measuring the first-derivative signals of IMP and GMP at 253 and 248 nm, respectively, simultaneous determination was possible for IMP and GMP at 5-40 micrograms/mL, in the presence of up to 5000 micrograms/mL MSG. The method was satisfactorily used to determine IMP and GMP in several food preparations.