ASTM D4815 for elements in gasoline by gas chromatography
ASTM D4815 Standard Test Method for Determination of MTBE, ETBE, TAME, DIPE, tertiary-Amyl Alcohol and C1 to C4 Alcohols in Gasoline by Gas Chromatography
1. Scope
1.1 This test method covers the determination of ethers and alcohols in gasolines by gas chromatography. Specific compounds determined are methyl tert-butylether (MTBE), ethyltert-butylether (ETBE), tert-amylmethylether (TAME), diisopropylether (DIPE), methanol, ethanol, isopropanol, n-propanol, isobutanol, tert-butanol, sec-butanol, n-butanol, and tert-pentanol (tert-amylalcohol).
1.2 Individual ethers are determined from 0.1 to 20.0 mass %. Individual alcohols are determined from 0.1 to 12.0 mass %. Equations used to convert to mass % oxygen and to volume % of individual compounds are provided.
1.3 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.
1.4 Benzene, while detected, cannot be quantified using this test method and must be analyzed by alternate methodology (see Test Method D3606 or D4420).
1.5 The values stated in SI units are to be regarded as standard. Alternate units, in common usage, are also provided to increase clarity and aid the users of this test method.
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:
D1298 Test Method for Density, Relative Density (Specific Gravity), or API Gravity of Crude Petroleum and Liquid Petroleum Products by Hydrometer Method
D1744 Test Method for Water in Liquid Petroleum Products by Karl Fischer Reagent
D3606 Test Method for the Determination of Benzene and Toluene in Finished Motor and Aviation Gasoline by Gas Chromatography
D4052 Test Method for Density and Relative Density of Liquids by Digital Density Meter
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4307 Practice for Preparation of Liquid Blends for Use as Analytical Standards
D4420 Test Method for Determination of Aromatics in Finished Gasoline by Gas Chromatography
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 low volume connector - a special union for connecting two lengths of tubing 1.6-mm inside diameter and smaller. Sometimes this is referred to as zero dead volume union.
3.1.2 oxygenate - any oxygen-containing organic compound that can be used as a fuel or fuel supplement, for example, various alcohols and ethers.
3.1.3 split ratio - in capillary gas chromatography, the ratio of the total flow of carrier gas to the sample inlet versus the flow of the carrier gas to the capillary column, expressed by
split ratio = (S + C)/C
where:
S = flow rate at the splitter vent, and
C = flow rate at the column outlet.
3.1.4 tert-amyl alcohol - tert-pentanol.
3.2 Acronyms:
3.2.1 DIPE - diisopropylether.
3.2.2 ETBE - ethyl tert-butylether.
3.2.3 MTBE - methyl tert-butylether.
3.2.4 TAME - tert-amyl methylether.
3.2.5 TCEP - 1,2,3-tris-2-cyanoethoxypropane - a gas chromatographic liquid phase.
3.2.6 WCOT - a type of capillary gas chromatographic column prepared by coating the inside of the capillary with a thin film of stationary phase.
