analysed on two fused silica capillary columns, a DB5-type (CPSil8
CB low bleed/MS – 5% diphenyl/95% dimethyl polysiloxane
60 m 0.25 mm I.D 25 lm film thickness; Varian, Palo Alto,
CA) and a Carbowax type (Supelcowax-10 – 60 m 0.25 mm
0.25 lm film thickness; Supelco). A retention gap coiled in five
small loops was attached to the front of the column. This was
cooled with solid CO2 contained in a beaker during desorption of
the fibre.