Characterisation of dissolved organic compounds in hydrothermal fluids by stir bar sorptive extraction - gas chomatography - mass spectrometry. Case study: the Rainbow field (36°N, Mid-Atlantic Ridge)

Table 4 Retention times (Rt _stds ) of C ₉ -C ₂₀ n-alkanes obtained by SBSE-TD-GC-MS analyses of a standard mixture (10 μg/L)

Compounds	Molecular formula	Rt _stds (min)	Rt _fluids (min)
nonane	C9H20	4.75	4.76
decane	C10H22	6.01	6.05
undecane	C11H24	7.28	7.32
dodecane	C12H26	8.49	8.52
tridecane	C13H28	9.65	9.70
tetradecane	C14H30	10.74	10.79
pentadecane	C15H32	11.77	11.81
hexadecane	C16H34	12.77	12.81
heptadecane	C14H36	13.69	13.74
octadecane	C18H38	14.57	14.62
nonadecane	C19H40	15.41	15.47
eicosane	C20H42	16.21	-

Detection of the compounds was achieved using ions m/z 57 and 85. The NIST08 library was used for identification. Retention times (Rt _fluids) obtained in hydrothermal fluids samples of this study are given for direct comparison.

ISSN: 1467-4866