Determination of Monosodium Glutamate in Noodles Using a Simple Spectrofluorometric Method based on an Emission Turn-on Approach.

A simple, fast, and ecofriendly spectrofluorometric method was developed and validated for determination of mono sodium glutamate (MSG). The method depended on the reaction between MSG and iron (III) salicylate based on ligand exchange mechanism. Addition of MSG turned-on the fluorescent response of iron (III) salicylate at λem 411 nm. Reaction conditions including reagent concentration, pH, and time were optimized. The method was validated regarding the ICH guidelines. The method determined MSG within the linearity range of 25-250 µM with a coefficient of determination of 0.9967 and a calculated limit of detection of 1.73 µM. Furthermore, the developed method was successfully applied for the determination of MSG in food preparation (instant noodles). The results were compared to those obtained by a published HPLC method using t-test and F-test at 95% confidence interval; no statistically significant difference was found. Based on the analytical Eco-scale and the green analytical procedure index (GAPI), the developed method was assessed to be greener than the published HPLC method. The developed method offered advantages over other spectrophotometric reported methods and was convenient for routine determination of MSG in foodstuffs.