(A) is an overlay of TD-GC-MS TIC traces of SBSE extracts of 8 aliquots of the same fluid sample from the Rainbow hydrothermal vent field in 2008 (refer to Table2and Figure2). Offset of the traces was enabled for clarity. Seven stir bars, T91 to T97, were analysed on the same day; the last one, T98 (top trace) was analysed one day after. Peaks highlighted in grey are the Twister® characteristic peaks. The bottom trace was obtained for the dry blank experiment T100 (refer to § Sample collection and preparation and § Blank and control experiments) and is characteristic to a clean conditioned Twister® (2 h, 300°C, He 50 mL min-1). Note that the scale for the latter is different.