The aqueous micelle phase
has been separated by centrifugation, then it was treated with a mixture of H2O: CHCl3 and ultrasonic
vibration, were used to effectively back-extraction of the analytes into the chloroform phase. The sedimented
organic phase was obtained after centrifugation, withdrawn into the microsyringe and directly
injected into the GC–FID system. The calibration graphs were linear in the range 0.05–20 mg L1. The
limits of detection were in the range of 0.02–0.15 mg L1. This procedure was successfully applied for
determination of propanal, butanal, hexanal and heptanal in real heated oil samples.