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available. The main reason for this re-analysis was the comparability with other data
quantified by ECNI (mostly applied world-wide).
5.4.3.3 Interpretation of PCA concentrations
Table 34 summarises concentrations of total PCA and formula-specific results for
sPCAs and mPCAs in all sediments. Figure 15 shows a site-specific survey of the total
PCA levels. The following conclusions and comparisons could be made:
• EI-MS/MS allowed detecting PCAs in all sediments (5-377 ng/g dry weight (dw),
see Table 34 for details). Quantification with different reference standards (e.g. a
short-chain and medium chain references) agreed well.
• Sum PCA concentrations determined by EI-MS/MS and CH4/CH2CI2-NICI were
comparable within 10-15 % with a few exceptions.
• PCA levels in sediments from the Baltic Sea (45-377 ng/g dw) were generally
higher than in those from the North Sea (5-355 ng/g dw, ten of sixteen samples
below 50 ng/g dw). However, they were quite equal on TOC basis (North Sea 2.3-
33.1 ng/g TOC, Baltic Sea 2.1-9.4 ng/g TOC)
• PCA concentrations in sediments have only been reported from only very few sites
world-wide (see Table 35). As already mentioned for biota, a comparison of levels
is hampered by different quantification procedures. Moreover, some locations were
contaminated by PCA production or release. Therefore, the published data allow
only the remark that total PCA concentrations (in ng/g dry weight) in sediments
from the North and Baltic Sea are about in the same range as those other of not
contaminated sites.
• A limited number of additional sediments were analysed from different regions of
Europe to increase the data base for comparison. This was not part of the project
study, but the results were also included in Table 35. As can been, PCA levels in
these river and sea sediments are comparable with those from the North and
Baltic Sea. One site at the river Seine estuary had an unusually low TOC content
(0.07 %), which resulted in a high PCA burden expressed on TOC basis.
