Determination of TAN and TBN (Total Number of Acids and Bases) (ASTM D664)

The ASTM D664 standard, developed by the American Testing and Materials Organization (ASTM), presents test methods for the determination of acidic components in petroleum products, lubricants, biodiesel and biodiesel blends.

The full name of this standard is: ASTM D664-18e2 Standard test method for the acid number of petroleum products by potentiometric titration.

The test methods described in this standard are:

• Test method A is for soluble petroleum products and lubricants in mixtures of toluene and propan-2-ol. Applicable to the determination of acids with dissociation constants greater than 10-9 in water. Extremely weak acids with dissociation constants less than 10-9 do not mix. Salts react if hydrolysis constants are greater than 10–9.
• Test method B was developed for biodiesel and biodiesel blends with low acidity and slightly different solubility. This test method requires the use of an automatic titrator with automatic endpoint search.

Components considered to be acidic in new and used oils include organic and inorganic acids, esters, phenolic compounds, lactones, resins, salts of heavy metals, ammonia salts and other weak bases, acid salts of polybasic acids, and additives such as detergents.

In the test, analysis, measurement and evaluation studies carried out in our organization, national and international standards and applicable legal regulations are complied with and reliable and impartial results are obtained. These studies are based on the latest technological equipment, trained and experienced staff and modern methods. TAN and TBN (total number of acids and bases) determination (ASTM D664) services are among the numerous tests performed in this context.