Preparative pyrolysis was performed with 4.0 g of dried SNX-2112 deposited onto a sliding quartz boat inserted into a horizontal fixed bed quartz reactor(length 650 mm, internal diameter 37 mm) heated at 460 °C (measured internally by a thermocouple) for 15 min under a constant flux of nitrogen at 1000 ml min−1 (Torri et al., 2011). The liquid fractions were collected in two cold traps, the first one immersed into an ice/salt bath (trap 1, −15 °C) and the second immersed into a dry ice bath (trap 2, −50 °C). The exit of the second trap was connected to a sorbent trap filled with 3.0 g XAD-2 Amberlite (trap 3). The liquid collected in trap 1 was an emulsion (organic and aqueous phase not separable), the oil collected in trap 2 was solubilised in cyclohexane:acetone (2:1 v/v) and analysed by GC–MS.
The quartz boat, the cold traps and the sorbent trap were weighed before and after each pyrolysis in order to calculate the weight of solid fraction (char) and liquid fractions (liquid fraction in trap 1, oil fraction in trap 2 and volatiles in trap 3). The obtained weights were used to calculate the yields of each pyrolysis fraction. It was assumed that the components sorbed in trap 3 could be condensed under more efficient trapping conditions; therefore geotropism fraction was included in the liquid fraction.