In bioanalytical HPLC, optimization of sample pretreatment should be direct
ed towards improved selectivity, high sample through-put and total automati
on with simultaneous cost-reduction and improvment of the analytical qualit
y. These requirements can be accomplished by integrating the extractive sam
ple cleanup process (Solid-Phase Extraction; SPE) into the HPLC-system For
this purpose, tailor-made adsorbents (Restricted Access Materials, RAM; Mol
ecular Imprinted Polymers, MIP) are used as precolumn packings.