ASTM D6839 for Hydrocarbon Types, Oxygenated Compounds and Benzene
ASTM D6839 Standard Test Method for Hydrocarbon Types, Oxygenated Compounds and Benzene in Spark Ignition Engine Fuels by Gas Chromatography
1. Scope
1.1 This test method provides for the quantitative determination of saturates, olefins, aromatics and oxygenates in spark-ignition engine fuels by multidimensional gas chromatography. Each hydrocarbon type can be reported either by carbon number (see Note 1) or as a total.
NOTE 1 - There can be an overlap between the C9 and C10 aromatics; however, the total is accurate. Isopropyl benzene is resolved from the C8 aromatics and is included with the other C9 aromatics.
1.2 This test method is applicable to spark-ignition engine fuel with total aromatic content up to 50 % (V/V), total olefinic content up to 30 % (V/V) and oxygen compounds up to 15 % (V/V).
1.3 This test method is not intended to determine individual hydrocarbon components except benzene.
1.4 Oxygenates as specified in Test Method D4815 have been verified not to interfere with hydrocarbons. Within the round robin sample set, the following oxygenates have been tested: MTBE, ethanol, ETBE, and TAME. Other oxygenates can be determined and quantified using Test Method D4815 or D5599.
1.5 The values stated in SI units are to be regarded as the 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 and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
D4307 Practice for Preparation of Liquid Blends for Use as Analytical Standards
D4814 Specification for Automotive Spark-Ignition Engine Fuel
D4815 Test Method for Determination of MTBE, ETBE, TAME, DIPE tertiary-Amyl Alcohol and C1 to C4 Alcohols in Gasoline by Gas Chromatography
D5599 Test Method for Determination of Oxygenates in Gasoline by Gas Chromatography and Oxygen Selective Flame Ionization Detection
D6293 Test Method for Oxygenates and Paraffin, Olefin, Naphthene, Aromatic (O-PONA) Hydrocarbon Types in Low-Olefin Spark Ignition Engine Fuels by Gas Chromatography
3. Terminology
3.1 Definitions:
3.1.1 oxygenate, n - an oxygen-containing organic compound, which may be used as a fuel or fuel supplement, for example, various alcohols and ethers.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 hydrogenation, n - the process of adding hydrogen to olefin molecules as a result of a catalytic reaction.
3.2.1.1 Discussion - Hydrogenation is accomplished when olefins in the sample contact platinum at a temperature of 180°C in the presence of hydrogen. The olefins are converted into hydrogen saturated compounds of the same carbon number and structure. Monoolefins and diolefins convert to paraffins while cycloolefins and cyclodienes convert to cycloparaffins.
3.2.2 trap, n - a device utilized to selectively retain specific portions (individual or groups of hydrocarbons or oxygenates) of the test sample and to release the retained components by changing the trap temperature.
3.3 Acronyms:
3.3.1 ETBE - ethyl-tert-butylether
3.3.2 MTBE - methyl-tert-butylether
3.3.3 TAME - tert-amyl-methylether
