Calcium Acetate\nDrug Produced from <i>Rapana\nvenosa</i> Invasive Gastropod Shells: Green Process Control Assisted\nby Raman Technology

The highly demanded calcium acetate (Ca­(CH<sub>3</sub>COO)<sub>2</sub>) for biomedicine and various industries constantly\nrequires\ngreen and low-cost methods of synthesis. In the present work, a sustainable\napproach to produce Ca­(CH<sub>3</sub>COO)<sub>2</sub> is reported\nas a proof of concept, processing for the first time as a starting\nmaterial the worldwide highly abundant Rapana venosa shells, which is a neglected biogenic waste with high economical\npotential due to the rich mineral and organic pigmentary content.\nA green synthesis involving an eco-friendly acetic acid has been optimized\nat room temperature, without any additional energy consumption, and\nthe resulting saturated Ca­(CH<sub>3</sub>COO)<sub>2</sub> solution\nwas further slowly evaporated in three stages to obtain white Ca­(CH<sub>3</sub>COO)<sub>2</sub> crystalline powder, without impurity traces.\nRaman spectroscopy provided efficient structural information for every\nstep of the process control, during demineralization as well as end\nproduct validation. Yields as high as 87.5% of highly pure Ca­(CH<sub>3</sub>COO)<sub>2</sub> mass have been achieved from raw R. venosa shells, proving the uniqueness and economic\nviability of the method. X-ray diffraction (XRD), scanning electron\nmicroscopy with energy-dispersive spectroscopy (SEM-EDX), and Fourier-Transform\nIR spectroscopy (FTIR) analyses validated the final product identity,\nhydration status, crystalline morphology, and composition. The purity\nof the resulting product suggests a high valorization potential of\nthe abundant R. venosa shell in the\ncontext of the blue bioeconomy and offers a cleaner and efficient\nmethod of Ca­(CH<sub>3</sub>COO)<sub>2</sub> production with important\napplications in relevant industries.