SARA oil testing measures saturates, asphaltenes, resins and aromatics in heavy crude oil, distillates and feedstocks. Saturates and aromatics are determined by HPLC. Asphaltenes can be pentane and heptane insolubles. Resins may be classified as solubility fraction.
Non-volatile Component Analysis
HPLC is unquestionably the most widely used of all of the analytical separation techniques. It is suitable for separating nonvolatile species or thermally fragile ones. Examples of such materials include amino acids, proteins, carbohydrates, pesticides, metalorganic species and a variety of inorganic substances.