ASTM D5441 Standard Test Method for Analysis of Methyl Tert-Butyl Ether (MTBE) by Gas Chromatography
1. Scope
1.1 This test method covers the determination of the purity of methyl tert-butyl ether (MTBE) by gas chromatography. It also provides a procedure to measure impurities in MTBE such as C4 to C12 olefins, methyl, isopropyl and tert-butyl alcohols, methyl sec-butyl and methyl tert-amyl ethers, acetone, and methyl ethyl ketone. Impurities are determined to a minimum concentration of 0.02 mass %.
1.2 This test method is not applicable to the determination of MTBE in gasoline.
1.3 Water cannot be determined by this test method and must be measured by a procedure such as Test Method D1364 and the result used to normalize the chromatographic values.
1.4 A majority of the impurities in MTBE is resolved by the test method, however, some co-elution is encountered.
1.5 This test method is inappropriate for impurities that boil at temperatures higher than 180 °C or for impurities that cause poor or no response in a flame ionization detector, such as water.
1.6 The values stated in SI (metric) units of measurement are preferred and used throughout the standard.
1.6.1 Exception - Alternate units, in common usage, are also provided to improve clarity and aid the user of this test method.
1.7 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.
1.8 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.
2. Referenced Documents
2.1 ASTM Standards:
D1364 Test Method for Water in Volatile Solvents (Karl Fischer Reagent Titration Method)
D3700 Practice for Obtaining LPG Samples Using a Floating Piston Cylinder
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4307 Practice for Preparation of Liquid Blends for Use as Analytical Standards
D4626 Practice for Calculation of Gas Chromatographic Response Factors
E355 Practice for Gas Chromatography Terms and Relationships
E594 Practice for Testing Flame Ionization Detectors Used in Gas or Supercritical Fluid Chromatography
3. Terminology
3.1 Definitions - This test method makes reference to many common gas chromatographic procedures, terms, and relationships. Detailed definitions of these can be found in Practices E355 and E594.
3.2 Definitions ofTerms Specific to This Standard:
3.2.1 C4 to C12 olefins - common olefin impurities in MTBE are unreacted feedstock and dimers or trimers of feed such as trimethylpentene or pentamethylheptene.
