Summary
The
authors describe a method to determine 12 dioxin-like polychlorinated
biphenyls (dl‑PCBs) in feed and foods of animal origin using
high resolution gas chromatography and mass spectrometry (HRGC-HRMS).
The use of semi-automated apparatus such as an accelerated solvent
extraction device and the Power-Prep purification system significantly
reduced the sample treatment time necessary before instrumental
analysis in comparison with the Soxhlet extraction method or manual
purification on columns traditionally used. This method demonstrated
good specificity (mild interference limited to PCB 81 and 123
in highly contaminated matrices, such as fish and fish feed), with
limits of detection of 0.2‑1.3 pg/g of fat. The coefficients
of variation for repeatability tests were in the range of 2.6‑18.3%,
with recoveries of over 80%. The method was successfully applied
to the analysis of 177 samples of various foodstuffs specified
in the 2005 Italian National Residues Plan: this is the first data
on dioxin-like PCB contamination levels in Italy to emerge under
this monitoring plan.
Keywords
Dioxins,
Feed, Foodstuffs, High resolution gas chromatography, High resolution
mass spectrometry, Dioxin-like polychlorinated biphenyls. |