ASTM D4864 Test Method for Determination of Traces of Methanol in Propylene Concentrates by Gas Chromatography
7. Apparatus
7.1 Gas Chromatograph - Any GC equipped with either flame ionization or thermal conductivity detectors with an overall sensitivity sufficient to detect at least 4 mg/kg of methanol.
7.2 Column - Any GC column that separates methanol from water, other alcohols, and any co-extracted hydrocarbons.
NOTE 2 - See Table 1 for a suitable list of columns and Fig. 1 and Fig. 2 for examples of chromatograms. Also, refer to Practice E260 for typical instructions in preparing such columns. Alternatively, columns can be purchased from commercial sources.
7.3 Data Handling System - Any commercially available GC integrator or GC computer system capable of accurately integrating the area of the methanol peak is satisfactory.
7.4 Recorder - A strip-chart recorder with a full scale response of 2 s or less and a maximum noise rate of +/- 0.3 % full scale.
7.5 Sample Cylinders, 300 mL capacity, stainless steel, Type DOT 3E (12409 kPa (1800 psig) working pressure).
7.6 Balances - Any types capable of weighing a 300 mL sample cylinder and contents accurately to 0.1 g and a 25 mL volumetric flask and contents accurately to 0.0001 g.
7.7 Plug Valve, 1/4 in. male NPT or optionally, 1/4 in. male NPT to 6.35 mm outside diameter (1/4 in.) tubing. (See 10.2.1.)
7.8 Shut-off Valves, 1/4 in. male NPT to 6.35 mm outside diameter (1/4 in.) tubing.
7.9 Regulating Valves, 1/4 in. male NPT and 1/4 in. male NPT to 1/4 in. female NPT.
7.10 Hex Nipple, SS, 1/4 in. male NPT by 102 mm (4 in.) long.
7.11 Hex Coupling, SS, 1/4 in. female NPT by 30 mm (1.2 in.) long.
7.12 Brass Cap, 1/4 in. NPT or optionally, a tube fitting nut, 6.35 mm outside diameter (1/4 in.). (See 10.2.1.)
7.13 Septum, TFE-fluorocarbon lined, 11 mm diameter.
7.14 Syringes, 10 µL and 25 µL.
8. Reagents and Materials
8.1 Methanol, reagent grade or better.
8.2 Propylene, 92 % plus purity containing <0.2 mg/kg (ppm mass) methanol.
