HyperSep? C18 is one of the most hydrophobic silica-bonded phases available. HyperSep C18 will retain most compounds from a polar matrix, so it is ideally suited for screening a wide variety of compounds. This non-polar sorbent is manufactured using a tri-functional silane and is non-endcapped. HyperSep C18 has wide applicability as it retains most organic analytes from aqueous matrices.