Determination of phenols in pyrolysis oil by on-line coupled microporous membrane liquid-liquid extraction and multidimensional liquid chromatography

An efficient and fast method was developed for the determination of phenols in pyrolysis oils. Microporous membrane liquid-liquid extraction (MMLLE) w as applied in sample pretreatment and samples were analyzed by multidimensi onal liquid chromatography. The pyrolysis oil was dissolved in a suitable o rganic solvent and then continuously pumped through the donor side of the M MLLE system. The acceptor solution was a highly basic aqueous solution, whi ch was kept stagnant during the extraction. The extract was transferred via a loop to the multidimensional LC system. Capillary electrophoresis was in vestigated for qualitative analysis of the extract. After separation, the p henols were identified by diode array detection and mass spectrometry. The method was quantitative, repeatable and linear, and limits of detection wer e in the range of 0.01-0.12%w/w.