ASTM D6733 Standard Test Method for Determination of Individual Components in Spark Ignition Engine Fuels by 50-Metre Capillary High Resolution Gas Chromatography
6. Apparatus
6.1 Instrumentation - A gas chromatograph capable of operating under the conditions outlined in Table 1, equipped with a split injector, a carrier gas pressure control, and a flame ionization detector which are required.
6.2 Sample Introduction System - Manual or automatic liquid syringe sample injection may be employed.
6.3 Data Acquisition System - Any data system can be used with a requirement:
6.3.1 Sampling rate of 10 Hz or more with a storage of sampling data for later processing.
6.3.2 Capacity for at least 400 peaks/analysis.
6.3.3 Identification of individual components from retention time; software can be used to automatically identify the peaks with the index system determined from Table A1.1 or Table A1.2.
6.4 Sampling - Two millilitres or more crimp-top vials and aluminum caps with polytetrafluoroethylene (PTFE)-lined septa are used to transfer the sample.
6.5 Capillary Column - A 50 m fused silica capillary column with an internal diameter of 0.2 mm, containing a 0.5 µm film thickness of bonded dimethylpolysiloxane phase is used. The features must be respected to reproduce the separation of the reference chromatogram. The column must meet the criteria of efficiency, resolution, and polarity defined in Section 10.
7. Reagents and Materials
7.1 Carrier Gas and Make-up, helium, 99.99 mol % pure. (Warning - Compressed gas under high pressure.)
7.2 Fuel Gas, hydrogen, hydrocarbon free, 99.99 mol % pure. (Warning - Compressed gas under high pressure. Extremely flammable.)
7.3 Oxidizing Gas, air, 99 mol %. (Warning - Compressed gas under high pressure.)
7.4 n-Pentane, 99+ mol % pure. (Warning - Extremely flammable. Harmful if inhaled.)
7.5 n-Hexane, 99+ % mol % pure. (Warning - Extremely flammable. Harmful if inhaled.)
7.6 n-Heptane, 99+ mol % pure. (Warning - Extremely flammable. Harmful if inhaled.)
7.7 2-Methylheptane, 99+ mol % pure. (Warning - Extremely flammable. Harmful if inhaled.)
7.8 4-Methylheptane, 99+ mol % pure. (Warning - Extremely flammable. Harmful if inhaled.)
7.9 n-Octane, 99+ mol % pure. (Warning - Extremely flammable. Harmful if inhaled.)
7.10 n-Dodecane, 99+ mol % pure. (Warning - Extremely flammable. Harmful if inhaled.)
7.11 Toluene, 99+ mol % pure. (Warning - Extremely flammable. Harmful if inhaled.)
7.12 System Performance Mixture - Weigh an equal amount of n-pentane, n-heptane, n-octane, n-dodecane, 2-methylheptane, 4-methylheptane, and toluene. Dilute this mixture in n-hexane to obtain a concentration of 2 mass % for each compound.
