For direct in-line sample preparation of untreated bio-fluids: LC-integrated sample preparation with LiChrospher® ADS is less expensive, less time consuming and more precise in comparison to conventional off-line sample preparation. LiChrospher® ADS allows the direct extraction and enrichment of hydrophobic, low molecular analytes from untreated samples such as haemolysed blood, plasma, serum, milk, salivary fluid, fermentation broth, supernatants of cell cultures and tissue as well as food homogenates. LiChrospher® ADS allows fully automated preparation of the sample prior to the analytes being separated in the column. This allows the untreated bio-fluid to be directly injected without negative effects on either the column or the results achieved. LiChrospher® ADS sorbents belong to the family of restricted access materials (RAM) with two chemically different surfaces. Extraction and fractionation with LiChrospher® ADS is based on the simultaneous performance of two chromatographic processes: reversed phase/ion-pair chromatography and size exclusion chromatography. Three types of ADS precolumns are available showing different hydrophobicity and retention and extraction properties for non polar sample compounds: LiChrospher® RP-4 ADS, LiChrospher® RP-8 ADS and LiChrospher® RP-18 ADS