Our research: Investigating freezing-induced acidity changes in citrate buffers
Susrisweta Behera, Radim Štůsek, and Lukáš Veselý, led by Dominik Heger (principal investigator at the Department of Chemistry), collaborated with the Austrian group of Thomas Loerting to conduct a comprehensive study of the behaviour of citrate buffer during freezing.
The study revealed that one of the most commonly used citrate buffers becomes more acidic when frozen. Interestingly, the acidification is more pronounced at lower concentrations, while it is negligible at higher concentrations. The authors conducted a calorimetric study and optical microscopy, correlating the results with the acidities obtained by spectroscopy. The study revealed that citrate buffer can crystallize, which challenges a long-standing paradigm in the pharmaceutical field. Additionally, the measured acidities demonstrate that citrate buffer significantly acidifies, which was previously unexpected.