ASTM D5186-22 PDF

Overview

ASTM D5186-22 outlines the Standard Test Method for Determination of the Aromatic Content and Polynuclear Aromatic Content of Diesel Fuels by Supercritical Fluid Chromatography (SFC). This test method is a crucial tool for accurately quantifying both monoaromatic and polynuclear aromatic hydrocarbon compounds in motor diesel fuels and blend stocks within the boiling range typical of these fuels. Using SFC, this method delivers results for aromatics in the 1% to 75% by mass range and polynuclear aromatic hydrocarbons from 0.5% to 50% by mass. The primary keywords associated with this standard include aromatic hydrocarbons, diesel fuel analysis, polynuclear aromatics, and supercritical fluid chromatography.

Key Topics

• Regulatory Compliance: The aromatic content of diesel fuels directly influences cetane number and exhaust emissions. Both the United States Environmental Protection Agency (USEPA) and California Air Resources Board (CARB) impose strict regulations on total aromatics and polynuclear aromatic hydrocarbons in diesel fuels. Accurate determination is essential for compliance with environmental regulations.

• Precision and Efficiency: Compared to alternative test methods such as ASTM D1319 and D2425, ASTM D5186-22 provides statistically improved precision and faster analysis times for typical diesel fuels, enabling more efficient laboratory workflows and better process control for fuel producers.

• Scope and Limitations: The method is applicable to diesel fuels and blend stocks not containing biodiesel, as the presence of biodiesel can interfere with results. The test is independent of fuel coloration, an advantage over some other methods.

• System Requirements: Implementation requires instrumentation capable of SFC, equipped with a flame ionization detector (FID), temperature and pressure controls, and precision sample injection systems, along with high-purity reagents to ensure reliable results.

Applications

• Fuel Quality Control: Refineries and fuel producers use ASTM D5186-22 for routine monitoring and quality assurance. The method provides accurate profiling of monoaromatics and polynuclear aromatic hydrocarbons, supporting consistent product quality and process optimization.

• Regulatory Testing: Laboratories rely on this test to ensure motor diesel fuels meet federal and state regulatory requirements for aromatic hydrocarbon content. The method supports reporting, compliance audits, and certification of products for environmental standards.

• Research and Development: The method proves valuable in the analysis of new fuel formulations and additives, especially when researching their impact on aromatics-related properties.

• Interlaboratory Consistency: ASTM D5186-22 includes procedures for assessing accuracy and precision through reference standards and quality control samples, establishing reliable and repeatable results across laboratories.

Related Standards

The following ASTM standards are referenced and closely related to ASTM D5186-22:

• ASTM D1319: Test Method for Hydrocarbon Types in Liquid Petroleum Products by Fluorescent Indicator Adsorption. Historically mandated for some regulatory purposes.
• ASTM D2425: Test Method for Hydrocarbon Types in Middle Distillates by Mass Spectrometry. Suitable for detailed hydrocarbon analysis but more costly and time-consuming.
• ASTM D6591: Test Method for Determination of Aromatic Hydrocarbon Types in Middle Distillates by High Performance Liquid Chromatography.
• ASTM D6299: Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measurement System Performance.
• ASTM D6708: Practice for Statistical Assessment and Improvement of Expected Agreement Between Two Test Methods That Purport to Measure the Same Property of a Material.

Practical Value

Implementing ASTM D5186-22 enables laboratories and fuel producers to:

• Accurately measure aromatic and polynuclear aromatic hydrocarbons in diesel fuels
• Ensure regulatory compliance with USEPA and CARB standards
• Improve quality control and process consistency
• Achieve faster, more precise, and reliable test results compared to traditional methods

By utilizing supercritical fluid chromatography, this standard delivers robust and repeatable aromatic content determinations, helping the fuel industry meet quality and environmental demands efficiently.