Reagents & Standards
Total Acid Number (TAN)
The procedures of the measurment of the TAN parameter varies depending on sample solubility in materials such as Toluene or Propan-2-ol, the dissociation constants of the acids in water, or the nature of the test sample. Therefore, the methodology used for lubricants may be different from the methodology used for biodiesel. In new and used oils the constituents that may be considered to have acidic characteristics include organic acids, inorganic acids, esters, phenolic compounds, lactones, resins, salts of heavy metals, acid salts of polybasic acids, and additives such as inhibitors and detergents.