This study proposed a method to determine the sum of the concentrations of inosine 5’-monophosphate (IMP) and guanosine 5’-monophosphate (GMP) in final and intermediate products through a combination of UV spectroscopy and multivariate calibration. Partial Least Squares regression (PLS regression) was used for the data analysis and the proposed methods presented errors of around 4 mg/L. In addition, the analysis cost is 10 times lower than the reference chromatographic method and the analytical frequency is 20 samples/hour.