2.4. Sample clean-up, POP analysis and quality control/quality assurance
2.5. Principal component analysis
3. Results and discussion
The chemical composition and carbon speciation differed between the ash samples (Table 1). Ash B had by far the highest chloride content (33%), while ash C had more copper than the other two. In terms of carbon compounds, ash A contained mostly organic carbon and carbonates, ash B contained mostly graphite while ash C had Semagacestat low, but even, distribution of the analyzed carbon species. The variation in carbon speciation could be partly due to variation in the type of active carbon used in the incinerators.
3.1. Screening study
3.2. Main study
3.2.1. Ash PCDF, PCDD, PCN and PCB concentrations
Fig. 2. Total concentrations and chlorination degrees of PCDFs (upper left panel), PCNs (lower left panel), PCDDs (upper right panel) and PCBs (lower right panel). The left-hand scale in each panel shows concentrations (pmol/g) and the right-hand scale chlorination degrees, i.e. average numbers of chlorine substituents on the carbon backbone calculated as Σ ((Homologue sum/Total sum) × No. of Cl). For PCNs and PCDDs, mono-chlorinated homologues were omitted, and for PCBs, mono-chlorinated and di-chlorinated PCBs were omitted.Figure optionsDownload full-size imageDownload as PowerPoint slide