The determination of the base number plays a significant role in the analysis of petroleum products. This is manifested in the numerous standard procedures in use around the world (internal specifications of multinational companies, national and international standards, e.g. ASTM, DIN, IP, ISO, etc.). These procedures differ mainly in the composition of the solvents and titrants used.
This bulletin describes the determination of the base number in petroleum products through the application of a wide variety of titration methods.
Potentiometric determination is described in accordance with ISO 3771 and photometric determination in accordance with ASTM D974. An ASTM standard is currently in the planning stages for thermometric titration. In addition, an explanation of conductometric determination in accordance with IP 400 is provided.