Determination of mono-ortho substituted chlorobiphenyls by multidimensional gas chromatography and their contribution to TCDD equivalents
✍ Scribed by Jacob de Boer; Quy T. Dao; Peter G. Wester; Søren Bøwadt; Udo A.Th. Brinkman
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- English
- Weight
- 938 KB
- Volume
- 300
- Category
- Article
- ISSN
- 0003-2670
No coin nor oath required. For personal study only.
✦ Synopsis
The mono-o&o chlorobiphenyls (CBS) 60,74,114,123,157,167 and 189 were determined in Aroclor mixtures and aquatic organisms by multidimensional gas chromatography with electron capture detection (MDGC/ECD), using a combination of an Ultra 2 and an FFAP column. MDGC/ECD is recommended as the most suitable technique for direct determination of these CBS, without a liquid chromatographic (LC) pre-separation of mono-o&o CBS from the other CBS. Dependent, to some extent, on the stationary phase used, single-column determinations of these CBS easily yield too high results due to the presence of interferences. The contribution of the mono-o&o CBS studied to the total 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) equivalents (TEQs) from CBS in fish is highly dependent on the toxic equivalency factors (TEFs) used and varies between 0.02 and 22%. This contribution is mainly due to CBS 74, 114, 157 and 167 which may easily be determined by taking three heart-cuts and combining them into one MDGUECD run. The analytical error is negligible compared with the huge uncertainty of the TEFs. A need for more precise TEFs is emphasized.