2.3.3. Extraction Extraction and concentration procedures were adapted from Lachenmeier et al. (2009). Each calibration solution or wine sample (25 mL) were spiked with 40 HL of internal standard s solution (final concentration of EC-ds equal to 32.6 ug L 1) and directly applied to the Extrelut column. After 15 min of equilibration, the column was washed with 2 x 20 mL of n-pentane (aiming at reduc- ing non-polar interferences of the wine matrix). The washing was discarded. Next, the analytes were extracted using 4 x 30 mL diethyl ether and the eluate collected in a 250 mL glass bottle (Schott Duran, Germany) and closed with screw PTFE-lined cap The bottle was then left at -20 oC for 48 h for the removal of resid ual moisture. It may be of interest to note that the elution flows of n-pentane and diethyl ether were increased considerably by manu- ally applying an over-pressure on top of column with a small hand rubber bellow.