Simplified spreadsheet approach for investigating polyprotic acid equilibria

Document Type : Original


Halal Research Center of IRI, Food and Drug Administration, Ministry of Health and Medical Education, Tehran, Iran.


Background and objective: Understanding how polyprotic acids behave is critical in various fields, including chemistry, biology, and medicine. Elucidation of the behavior of polyprotic acids through utilization of alpha functions, which provide insightful graphical representations of species distribution with varying pH levels, has been considered. The current paper offers an in-depth exploration of alpha functions and their significance in portraying the proportions of ionized and non-ionized species, a crucial aspect in predicting acid behavior, buffering capacity, and identifying optimal pH conditions.
Materials and methods: The Microsoft Excel and its Solver tool to explore polyprotic acid equilibria have been utilized. Synthetic datasets were generated using Excel spreadsheets, while Solver facilitated non-linear curve fitting for parameter optimization.
Results and conclusion: A novel contribution of this paper lies in introducing Excel-based tools that facilitate the generation of alpha function plots. These tools simplify the process of visualizing species distribution and pave the way for more advanced analyses. Additionally, the paper showcases the utilization of Excel Solver for robust nonlinear curve fitting of dissociation constants. This advanced computational technique enhances the accuracy of dissociation constant determination, ensuring more reliable predictions. An intriguing aspect of the proposed method is its ability to exhibit robustness even when the total acid concentration is unknown. This characteristic sets the approach apart, overcoming a common challenge in acid-base studies and analytical chemistry. The ability to accurately determine dissociation constants in such circumstances further underscores the practicality and relevance of the method. The implications of this research extend beyond the realm of theoretical understanding. The practical applications of the findings are particularly noteworthy, with a significant impact on pharmaceutical industries. The insights gained from alpha function analysis can be instrumental in drug formulation processes and in optimizing the solubility of pharmaceutical compounds. These applications can potentially enhance drug efficacy, patient experience, and overall healthcare outcomes.


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