ASTM D7756-19 - Standard Test Method for Residues in Liquefied Petroleum (LP) Gases by Gas Chromatography with Liquid, On-Column Injection

1.1 This test method covers the determination, by gas chromatography, of soluble hydrocarbon materials, sometimes called “oily residue,” which can be present in liquefied petroleum (LP) gases and which are substantially less volatile than the LPG product.

1.2 This test method quantifies, in the range of 10 mg/kg to 600 mg/kg (ppm mass), the residue with a boiling point between 174 °C and 522 °C (C₁₀ to C₄₀) in LPG. Higher boiling materials, or materials that adhere permanently to the chromatographic column, will not be detected.

1.3 Appendix X3, Appendix X4, and Appendix X6 describe additional applications which could be performed based on the hardware and procedures described in this test method. Appendix X3 describes a test procedure for expanding the analysis range to benzene, Appendix X4 describes a test procedure for the analysis of diisopropanolamine, and Appendix X6 describes a test procedure for the analysis of heavy residues or contaminants from C₄₀ to about C₆₀ in LPG.

1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.