【国外标准】 Standard Test Method for Determination of the Metal Deactivator Additive (MDA) (N,N′-disalicylidene-1,2-propanediamine) Content in Aviation Turbine Fuel by High Performance Liquid Chromatography (HPLC)

5.1 Specification D1655 provides a maximum permissible concentration (5.7 mg/L) of MDA in aviation turbine fuel. This test method will allow the quantification of MDA in aviation turbine fuels. The MDA additive is used for fuel thermal stability control and to reduce fuel degradation caused by the presence of trace metals (copper in particular) in aviation fuels.1.1 This test method covers the determination of the metal deactivator additive (MDA) content of aviation turbine fuels. The specific MDA determined and used to develop this test method is N,N′-disalicylidene-1,2-propanediamine. Other MDAs have not been tested by this test method.1.1.1 This test method specifically covers the determination of uncomplexed MDA content in aviation turbine fuel. MDA is a chelator of divalent metal ions, and the MDA-metal ion complexed species content of aviation turbine fuel will not be accounted for by this test method.1.2 This test method is divided into two procedures: (1) Procedure A uses a semi-portable capillary-liquid chromatography system (Capillary-HPLC) that may be used in the field or laboratory; (2) Procedure B uses a standard laboratory version of liquid chromatography (Conventional-HPLC). Procedures A and B have separate precisions.1.3 The test method has an interim repeatability determined in accordance with Practice D6300. Based on the mean values of the samples used in the interim repeatability study, Procedure A is applicable in the range of 0.50 mg/mL to 10.0 mg/mL; the range for Procedure B is 0.60 mg/mL to 9.6 mg/mL. Higher concentrations can be determined by dilution, but the precision of the test method has not been determined.1.3.1 An extended interlaboratory study (ILS) will be conducted in the future to determine the full repeatability and reproducibility and the final applicable concentration ranges.1.3.2 The test method applies to MDA in petroleum-based aviation fuels and Synthetic Aviation Fuels (SAF). However, for the interim precision, a petroleum-based aviation fuel was used. Future ILS will include petroleum-based and SAFs. The test method is applicable to aviation fuels conforming to Specification D1655.1.4 Appendix X2 indicates other additives that have been verified to not interfere with the analysis of this test method.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.