ASTM International

Standard Test Method for Determination of MTBE, ETBE, TAME, DIPE, tertiary-Amyl Alcohol and C1 to C4 Alcohols in Gasoline by Gas Chromatography
 N D4815 REV B

Annotation

This test method covers the determination of ethers and alcohols in gasolines by gas chromatography. Specific compounds determined are methyl tert-butylether (MTBE), ethyl tert-butylether (ETBE), tert-amylmethylether (TAME), diisopropylether (DIPE), methanol, ethanol, isopropanol, n-propanol, isobutanol, tert-butanol, sec -butanol, n-butanol, and tert-pentanol (tert-amylalcohol).

Individual ethers are determined from 0.20 mass % to 20.0 mass %. Individual alcohols are determined from 0.20 mass % to 12.0 mass %. Equations used to convert to mass % oxygen and to volume % of individual compounds are provided. At concentrations <0.20 mass %, it is possible that hydrocarbons may interfere with several ethers and alcohols. The reporting limit of 0.20 mass % was tested for gasolines containing a maximum of 10 volume % olefins. It may be possible that for gasolines containing >10 volume % olefins, the interference may be >0.20 mass %. Annex A1 gives a chromatogram showing the interference observed with a gasoline containing 10 volume % olefins.

This test method includes a relative bias correlation for ethanol in spark-ignition engine fuels for the U.S. EPA regulations reporting based on Practice D6708 accuracy assessment between Test Method D4815 and Test Method D5599 as a possible Test Method D4815 alternative to Test Method D5599. The Practice D6708 derived correlation equation is only applicable for ethanol in fuels in the concentration range from 2.28 % to 14.42 % by mass as measured by Test Method D4815. The applicable Test Method D5599 range for ethanol is from 2.16 % to14.39 % by mass as reported by Test Method D5599.

Alcohol-based fuels, such as M-85 and E-85, MTBE product, ethanol product, and denatured alcohol, are specifically excluded from this test method. The methanol content of M-85 fuel is considered beyond the operating range of the system.