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• Hordalub 500 did not fit into any group due to a high content of Cn (47 %) and
sample 721 due to a Co fraction of 78 %.
The picture was much more complex for mPCA:
• A certain similarity between Hordalub 80EM, Cloparin 50 and most of the
selected sediments could be observed. Since only two main congener groups are
present in mPCA (C14-15), changes in their concentration ratio will directly influence
the position in the principal components plot.
• The technical products Chlorparaffin 45fl, Hordaflex SP and the mixture from
Ehrenstorfer deviated much from sediments due to significantly different C14/C15
ratios.
The similarity of the PCA patterns of some technical products with those in sediments
might be an indication of ist major application. However, it cannot be excluded that
fractionation, accumulation and degradation processes in sediments might result in a
pattern similar to certain technical mixtures. Controlled degradation studies of technical
PCA in activated sewage sludge could answer this question at least partially.
Moreover, the similarities and differences in the principal component plots do not mean,
that a technical mixture is better suited as reference standard for quantification.
Response factors are also influenced by the chlorine content within each congener
group, which was not included in this comparison.