Total Acid Number and the use of Certified Reference Materials

Total Acid Number and the use of Certified Reference Materials

The Total Acid Number: A Crucial Indicator in Oil Analysis

The Total Acid Number (TAN) method is a critical procedure in oil analysis. It is a measure of the acidic constituents in petroleum products, which can indicate the oil's degradation level. The acid number is a crucial parameter that helps in determining the oil's quality and its remaining useful life.

The total acid number is calculated by titrating a solution of the oil sample with a base, usually potassium hydroxide, and measuring the amount of base required to neutralize the acid. The result is expressed in milligrams of potassium hydroxide per gram of oil (mg KOH/g oil). This value is the total acid number.

Total Acid Number Certified Reference Materials: Ensuring Accuracy in Measurements

To ensure the accuracy and reliability of the total acid number measurements, it is essential to use certified reference materials. Total Acid Number Certified Reference Materials (TAN CRMs) are substances with a known total acid number that are used as a benchmark to calibrate and / or verify equipment and validate the test results.

These reference materials should be produced under strict quality control procedures to ensure their consistency and accuracy. Reference Material Producers (RMPs) with accreditation to ISO 17024 ensure reference materials are produced correctly, certified values can be relied upon by the end-user, ensuring their reliability and credibility. Using TAN CRMs helps in achieving accurate and reliable total acid number measurements, which are crucial for effective oil analysis.

Acid Number Standard Test Methods for Reliable Oil Analysis

International standard test methods for acid number analysis play a vital role in oil analysis. These standards are established and published by recognised bodies such as the American Society for Testing and Materials (ASTM), Energy Institute (EI), the International Organisation for Standardisation (ISO), and other recognised bodies.

The international standard test methods published specify the methods and techniques used for determining the total acid number, e.g., ASTM D664 and IP 177. These international standard test methods are designed specifically for use in determining acid number in petroleum products by potentiometric titration, including the type of titrant to be used, the procedure for the titration, and the calculation of the total acid number. Adhering to these standards ensures that the total acid number measurements are accurate and reliable, which is crucial for effective oil analysis.

In conclusion, the total acid number method is a critical procedure in oil analysis. It provides valuable information about the oil's condition, which can help in determining its quality and remaining useful life. The use of total acid number certified reference materials ensures the accuracy and reliability of the total acid number measurements, making them a crucial part of effective oil analysis.

ARO Scientific offer a range of Total Acid Number (TAN) / Acid Number (AN) Certified Reference Materials that have been characterised in accordance with ASTM D664, Method A. Manufacture and characterisation has been performed in accordance with its accreditation to ISO/IEC 17025 and ISO 17034, UKAS CAB No. 27393.