论文部分内容阅读
In the present work,we developed a novel dispersive microextraction technique by combining the advantages of liquid-phase microextraction (LPME) and magnetic solid-phase extraction (MSPE).In this method,trace amount of water was directly absorbed on bare Fe3O4 to form water-coated Fe3O4 (W-Fe3O4) and rapid extraction can be achieved while W-Fe3O4 dispersed in the sample solution.The analyte adsorbed W-Fe3O4 can be easily collected and isolated from sample solution by a magnet.It was worth noting that in the proposed method water was used as extractant and Fe3O4 was served as the supporter and retriever of water.The performance of this method was evaluated by extraction of 3-monochloropropane-1,2-diol (3-MCPD) from edible oils.The extracted 3-MCPD was derived by a silylanization reagent (1-trimethylsilylimidazole) before gas chromatography-mass spectometry (GC-MS) analysis.Several parameters that affect the extraction and derivatization efficiency were investigated.Our results showed that the limit of detection for 3-MCPD was 1.1 ng/g.The recoveries in spiked oil sample were in the range of 70.0-104.9％ with the RSDs less than 5.6％ (intra-day) and 6.4％ (inter-day).Taken together,the simple,rapid and cost-effective method developed in current study,offers a potential application for the extraction and preconcentration of hydrophilic analytes from complex fatty samples.