TD-GC-MS TIC traces of SBSE extracts of 2 aliquots of the same fluid sample collected in 2005 from the Rainbow hydrothermal vent field. Duplicate experiments are routinely carried out and here is a representative example of what was generally observed. T11 (refer to Table 2) was analysed in 2005 (top trace), whereas T10 (refer to Table 2) was analysed 3 years later (bottom trace). Examples of peaks that were not repetable are: (a) toluene; (b) benzene, chloro-; (c) oxime, methoxyphenyl; (g) decane, 1-chloro; (h) naphthalene, 2-chloro; (i) siloxane; (k) diethylphthalate; (m) benzene sulfonylbis, [4-chloro]. Black triangles refer to n-carboxylic acids with the number being the carbonated chain length.