To overcome these analytical problems, we have attempted to apply a freezing lipid precipitation (FLP) method and strong cation exchange (SCX)-SPE for the effective cleanup of the samples. The FLP method has been successfully applied to eliminate the large amounts of lipids extracted from biota samples withhigh lipid contents [19,20]. During the FLP procedure, lipids inorganic extracts are precipitated frozen at −24◦C in the refrig-erator, and then, the frozen lipids can be easily removed by just filtering the extracts. Moreover, the FLP method has several advantages over conventional methods with respect to effective sample cleanup and the relative ease in which it can be combined with SPEcleanup. In this study, the elimination efficiency of lipids by freezinglipid precipitation was also examined by LC-atmospheric pressurechemical ionization (APCI)-MS. For further cleanup, a SCX-SPE car-tridge using a specific eluent was applied. The SCX-SPE method hasbeen used for the separation of basic analytes from co-extractedcontaminants