Significance and Use
5.1 Antioxidants are added to the aviation turbine fuels as protection against oxidation and formation of gums. Fuel system icing inhibitors are used to avoid ice formation in jet fuel under cold environment. The concentration of antioxidants and fuel system icing inhibitors is very important for the storage, trade and use of aviation turbine fuel. A standard test method for accurately measuring their contents and determination of specification limits is required to protect the fuels and engine performance. Test Method D5006 describes the analysis of one icing inhibitor; however, Test Method D5006 is more for field use and does not selectively identify or quantify the individual fuel system icing inhibitors. Several aviation turbine fuels specifications, such as Specification D1655, GB 6537, DEF-STAN 91-091 do not specify selective test method(s) for the listed additives.
Scope
1.1 This test method covers the determination, in the interim precision ranges, of hindered phenolic antioxidants from approximately 1 mg/L to 50 mg/L and fuel system icing inhibitors from approximately 450 mg/L to 4500 mg/L in aviation turbine fuels by solid phase extraction (SPE) with gas chromatography-mass spectrometry detection (SPE-GC/MS).
1.1.1 Higher concentrations can be determined, but the interim precision of the test method has not been determined.
1.2 This test method is applicable to aviation turbine fuels that meet several international aviation turbine fuel specifications including, but not limited to, petroleum based, such as specified in Specification D1655, and synthetic aviation turbine fuels (SAF), such as specified in Specification D7566, and a blend of such fuels.
1.3 The test method does not purport to identify all of the individual antioxidants and fuel system icing inhibitors. The interim precision estimates have been determined in accordance with Practice D6300 for the following:
1.3.1 Phenolic Antioxidants—2,6-di-tert-butyltert-butylphenol; 2,4,6-tri-tert-butylphenol; 2,6-di-tert-butyl-4-methyl phenol; 4-sec-butyl-2,6-di-tert-butylphenol; 2-tert-butyl-4,6-dimethylphenol; 2-tert-butylphenol; 4-tert-butyl-2-methylphenol; and
1.3.2 Fuel System Icing Inhibitors—Diethylene glycol monomethyl ether (DiGME) and ethylene glycol monomethyl ether (EGM) (2-methoxyethanol).
1.3.3 Not all of the above antioxidants and/or fuel system icing inhibitors may be listed in all aviation turbine fuel specifications. User should consult the pertinent specification(s) for testing requirements.
1.4 Appendix X1 presents information on the data such as accuracy recovery studies and application to several types of aviation turbine fuels.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 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.
1.7 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.
