Direct determination of Benzo[a]pyrene in oil distillates by on-line two-dimensional HPLC with column switching

Summary A selective and sensitive HPLC method for the determination of Benzoa]pyrene (Ba]p) in oil fractions by means of column switching is described. The diluted oil samples were injected directly onto a silica column with isooctane as eluent. After fast elution of the main part of the sample matrix, the Ba]p containing fraction was transferred on-line to a dinitro-aryl-modified silica column for final separation with isooctane/tetrahydrofuran. A detection limit of 50 ppt Ba]p was found when using fluorescence detection.Dedicated to Professor Leslie S. Ettre on the occasion of his 70th birthday.