Which substance is commonly used as a buffer in arterial fluid?

The correct answer is E.D.T.A. (ethylene diamine tetraacetic acid), which is commonly used as a chelating agent in arterial fluid formulations. E.D.T.A. helps to bind metal ions, which can interfere with the preservation process, ensuring that the arterial fluid functions effectively in preserving and disinfecting tissue. This buffering action plays a crucial role in maintaining the pH and enhancing the performance of the embalming fluid.

Formaldehyde, while a key preservative in embalming fluids, does not serve the specific role of a buffer; it is primarily responsible for cross-linking proteins and killing microorganisms. Alcohol is often used in various forms of disinfection and preservation, but it does not function as a buffer in arterial fluids. Sodium chloride can enhance the osmotic effects in embalming but is not primarily used as a buffering agent. Thus, E.D.T.A. is recognized for its ability to stabilize the embalming fluid, making it the appropriate choice in this context.