Sample preparation for GC/MS analysis of hydrophobic environmental contaminants by direct serum injection into restricted-access reversed-phase HPLC columns

The extraction of polychlorinated biphenyls and polyaromatic hydrocarbons from serum was studied by reversed phase liquid chromatography using restricted-access reversed-phase packing materials. The restrictive dimensions of the hydrophobic pores of the superficially hydrophilic packings excluded serum proteins and facilitated retention of the smaller hydrophobic compounds included in the buffer-acetonitrile injection mixture. Only a relatively short time was required for analytes to be separated from less hydrophobic serum components and recovered with acetonitrile elution, providing samples for GC/MS quantification. The factors involved with injections of larger volumes of serum are addressed.