Environmental pollutions and food contaminations are biggest social concerns, nowadays.Because of the complex matrices in environmental substances and food stuffs, sample preparations for the quantitative analysis of toxic and hazardous compounds with chromatographic instruments are inevitable in order to obtain reliable results.Liquid chromatography mass spectrometry (LCMS) have become the important means in the areas of qualitative and quantitative analysis of environmental monitoring and trace amount of contaminants in food stuffs.Although the performances of sensitivity and selectivity of this instrument have rapidly been improved in recent years, the sample pretreatment procedures remain the bottleneck for rapid analysis.Therefore, economical and effective pretreatment methods to eliminate matrix interferences, to achieve high throughout and to enrich the analyte for high sensitive detection are demanded.