We developed simple and cost-effective screening methods for dioxins (PCDD/DFs, Co-PCBs) in feed materials such as fish oil, which contains relatively high levels of these compounds. A 1 g of fish oil, the volume of which is one-tenth that required for the reference method, was efficiently purified by mixing with sulfuric acid-silica gel and passing through a tandem column consisting of acid-silica gel and active carbon. Forty-seven fish oil samples were applied to CALUX (chemically activated luciferase gene expression) assay, which has been shown to be a sensitive bioassay for dioxins. Fifteen fish oil samples were applied to a commercially available ELISA kit (EnBio Coplanar PCB EIA System) based on a monoclonal antibody against PCB118. Good correlations were observed between the two bioanalytical methods and the reference method using HRGC/HRMS (high-resolution gas chromatography/mass spectrometry) with respect to the TEQ (toxic equivalent) for dioxins. The running time and cost per sample for the developed screening methods were estimated to be roughly one-tenth to one-fourth and one-fifth to one-third those of the reference method, respectively, based on analysis of 25 fish oil samples. It should be noted that applying the CALUX assay rather than the ELISA kit is preferable in the case of feed samples other than those of fish origin, because the dioxin congener profiles are expected to vary from one sample to another.
(Safety Research Team, TEL +81-29-838-7708)
Reference:
- Hasegawa et al. (2007) Chemosphere 69 : 1188-1194.
- Hasegawa et al. (2007) Organohalogen Compounds 69 : 126-129.
