BS EN 14110:2003 – Fat and oil derivatives — Fatty Acid Methyl Esters (FAME) — Determination of methanol content

BS EN 14110:2003 - Fat and oil derivatives — Fatty Acid Methyl Esters (FAME) — Determination of methanol content

1 Scope
This European Standard specifies a method for the determination of methanol content in fatty acid methyl esters (FAME) for use as diesel fuel and domestic heating fuel. The method is applicable for a concentration range from 0,01 % (m/m) to 0,5 % ( m/m ) methanol. The method is not applicable to mixtures of FAME which contain other low boiling components.
2 Principle
The sample is heated at 80 °C in a hermetically sealed vial to allow desorption of contained methanol into the gas phase. When equilibrium is reached, a defined part of the gas phase is injected into a gas chromatograph, where methanol is detected with a flame ionisation detector. Normally methanol is the only peak in the chromatogram.
The amount of methanol is calculated by reference to an external calibration. Methanol can also be determined after addition of an internal standard to the sample before heating, followed by calculation with the use of an internal calibration factor.
NOTE If only manual equipment is available then only internal standard calibration should be used.
3 Reagents
Use only reagents of recognized analytical grade, unless otherwise specified.
3.1 Methanol, of known purity greater than 99,5 %.
3.2 2-propanol, of known purity, greater than 99,5 % (for procedure A, internal calibration).
3.3 Reference FAME, with a methanol content less than 0,001 % ( m/m ).
NOTE Reference FAME can either be obtained from commercial sources or by washing by three or five times with distilled water in a separator funnel. FAME should be then dried by heating at 90 °C under stirring and reduced pressure.
3.4 Carrier gas, nitrogen, helium or hydrogen, of know purity greater than 99 %.
4 Apparatus
4.1 Septum vials, 20 ml capacity.
4.2 Inert septa (e.g. TFE or Viton 1) ) and metallic caps.
4.3 Syringe, 10 µl, accurate to 0,1 µl.
4.4 Gas syringe 500 µl, fitted with a valve (for manual procedure).
4.5 Crimping pliers.
4.6 Pipettes, of 1 ml, 2 ml, 5 ml capacity.
4.7 Volumetric flask, capacity 10 ml and 25 ml.
4.8 Gas chromatograph, equipped with a capillary column, suitable injector (automatic headspace system or a split/splitless injector) and flame ionisation detector, integrator.
4.9 Capillary column, the column shall eluate methanol as a symmetrical peak. Stationary phases like methylpolysiloxane (e.g. DB1 2) , SE30 2) ) or polyethylenglycol (e.g. DBWAX 2) , CAR-BOWAX 2) ) can be used successfully and a film thickness of minimum 0,5 µm is recommended. NOTE The use of a packed column equipped by one of the above mentioned stationary phases or of Chromosorb 101 2) is also allowed.
4.10 Automatic headspace equipment The automatic headspace equipment used shall have a repeatability of 1 % or better concerning experimental conditions like equilibrium temperature, heating times, and headspace sampling volume. This can be checked, if necessary, by repeated analysis of the same sample.
BS EN 14110:2003 – Fat and oil derivatives — Fatty Acid Methyl Esters (FAME) — Determination of methanol content

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