scope:

This document describes a gas chromatography - ion mobility spectroscopy (GC-IMS) method for the determination of the concentration of siloxanes in biomethane. The method is applicable to the following siloxanes: -     hexamethyldisiloxane (L2); -     octamethyltrisiloxane (L3); -     decamethyltetrasiloxane (L4); -     dodecamethylpentasiloxane (L5); -     hexamethylcyclotrisiloxane (D3); -     octamethylcyclotetrasiloxane (D4); -     decamethylcyclopentasiloxane (D5); -     dodecamethylcyclohexasiloxane (D6). This document describes suitable calibration and measurement strategies to quantify siloxanes in (bio)methane around and above the 0,3 mg m-3 (14 µmol mol-1) level and applies to analyses within absolute pressure ranges of 1 bar - 2 bar, temperatures of 0 °C - 40 °C and relative humidity < 90 %.