A new sample preparation technique for organochlorines in cod liver oil combining SPE and NP-HPLC with HRGC-ECD

The analysis of semivolatile organochlorines (polychlorinated biphenyls and chlorinated pesticides) in less polluted biomaterials requires specific st rategies in controlling the blank in sample preparation. The procedure desc ribed here allows to decrease significantly the level of contamination duri ng the clean-up step of fish oil. Solid-phase-extraction (SPE) on LiChrolut (R) EN and normal phase HPLC in the normal- and the backflush-mode were use d to reduce the amount of solvents needed and the analysis time compared to established clean-up procedures. With a certified reference material (BCR- CRM 349; Cod Liver Oil) the precision and effectiveness of the new method w ere validated. Recovery rates of the Internal Standards (PCB 103 and TCN) l ay between 75% and 90% at the mu g/kg lipid level, The quantitative analyse s were carried out by high resolution gas chromatography with electron capt ure detector (HRGC-ECD).