Dimethyl ether [DME] fuel for purpose-built engines and DME-LPG blending shall conform to the requirement prescribed in ASTM D7901. Methanol, an oxygenate, is required for analysis in D7901 Table 1 by D2163 Test Method for Determination of Hydrocarbons in Liquefied Petroleum (LP) Gases and Propane/Propene Mixtures by Gas Chromatography (GC). The prescribed test methods for analysis of DME components were originally derived from a similar methodology used for hydrocarbon gases and liquid analysis.
In collaboration with testing laboratories, an alternative procedure specifically intended for the determination of methanol in DME and DME-blend samples was developed. This procedure will be described in the following proposed appendix.