This document describes the detailed hydrocarbon analysis (DHA) of spark ignition engine fuels by gas chromatography using the ASTM D 6730 method. The method is applicable to mixtures containing oxygenate blends (MTBE, ETBE, ethanol, etc.) with concentrations ranging from 0.01 to 30 mass%.
This document details a gas chromatography (GC) method for the detailed hydrocarbon analysis (DHA) of gasolines and other light liquid hydrocarbon mixtures. The method follows the ASTM D 6730 standard and is applicable to samples containing oxygenate blends with boiling ranges up to 225 °C. It is noted that the method is less suited for samples containing over 25 mass% of olefins due to potential interfering co-elution.
The procedure utilizes a Varian 450-GC Gas Chromatograph equipped with specific columns (Varian CP-Sil PONA CB and Varian CP-Sil 8 CB), a split/splitless injector, and FID detection. The analysis involves a specific column temperature program and carrier gas flow. Results are processed using Galaxie GC Workstation with integrated DHA software to generate reports on component concentrations, hydrocarbon grouping, and physical properties such as boiling point distribution and Reid vapor pressure.
| Applicable Boiling Range | up to 225 °C |
|---|---|
| Concentration Range | 0.01 to 30 mass% |
| Maximum Olefin Content | 25 mass% |
| Column Type 1 | Varian CP-Sil PONA CB |
| Column Type 2 | Varian CP-Sil 8 CB |
| Detector | FID |
| Carrier Gas | Helium |
| Split Ratio | 1:150 |
The method follows the ASTM D 6730 standard for the determination of individual components in spark ignition engine fuels.
Yes, the method is applicable to mixtures containing oxygenate blends such as IMTBE, ETBE, and ethanol.
The Galaxie GC Workstation is used for control and data handling, with DHA software fully integrated for calculations.