Chromatographic conditions and sample preparation were as described by Lytra et al. (2014b), inspired by Anocibar-Beloquietal. (1996). A 100-mL sample was placed in a 125-mL vial at room temperature and 10 lL of the internal standard (thiophene 330 mg/L) were added. The vial was then sealed using a screw-top cap with a Teflon-faced septum. After 24 h at 22 C and away from direct light, 1 mL of gaseous phase was injected using the headspace technique (HS). DMS was assayed by injection into an HP-5890 gas chromatograph coupled to a flame photometric detector (injector temperature: 70 C, interface temperature: 150 C), using an HP5 column. The oven was programmed at 30 C for the first minute, raised to 100 C at 10 C/min, and, finally, increased at 20 C/min to a final isotherm at 180 C. The carrier gas was hydrogen 5.5 (Air Liquide, France).