Purity determination of glutamic acid by DSC

Objective: The feasibility of the determination of glutamate purity was studied by differential scanning calorimetry. Methods: Indium and Zinc were used to correct the instrument parameters. Under the conditions of nitrogen atmosphere and flow rate of 50 mL/min, the effects of sample particle size, experimental atmosphere, heating rate and sample quality on the DSC measurement results were investigated, and the glutamic acid purity was determined under the optimal conditions. The determination results were compared between DSC and China Pharmacopeia 2015 titration. Results: Under the condition of weighing 3 mg and heating rate at 40 ℃/min, the purity of glutamic acid was 99.74% and the precision was 0.07%. The purity of glutamic acid measured by titration 99.72%. Conclusion: The DSC method has high accuracy and simple operation, and can be used for the determination of glutamate purity.