On-line preconcentration and high-performance liquid chromatographic determination of polycyclic aromatic hydrocarbon - DNA adducts using copper phthalocyanine trisulfonic acid as a group-specific adsorbent

An on-line preconcentration high-performance liquid chromatography system for the determination of polycyclic aromatic hydrocarbon-DNA adducts such as trihydroxytetrahydrobenzo[a]pyrene-deoxyguanotide in a DNA hydrolysate is described. Restricted-access copper phthalocyanine (CP) diol modified silica was used as a group-specific sorbent. For the determination of the benzo[a]pyrene adduct, two preconcentration columns (precolumns) in a dual-precolumn setup were used. Elution of the benzo[a]pyrene adduct from the CP precolumn was performed with 100% methanol. The analyte was re-concentrated on a C₁₈ precolumn applying on-line dilution with water. The C₁₈ precolumn can be desorbed with the LC mobile phase used for the analytical column. Trihydroxytetrahydrobenzo[a]pyrene-deoxyguanotide was determined in a DNA hydrolysate using the dual-precolumn procedure. A recovery of 95% was achieved. With fluorescence detection, a mass detection limit of 0.1 pmol injection was obtained.