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5.3.6 Analysis of chlordane compounds 
The analysis of chlordane compounds is well established and mainly carried out by 
ECNI mass spectrometry with low resolution instruments. Detailed information about 
state-of-the-art can be found in Karlsson (1999) and Karlsson el al. (2000). Usually, the 
four representatives c/.s'//ran.s-chlordanc and cis/lran.v- nonach 1 or as well as the main 
metabolites of c/.s'//ran.s-chlordanc are quantified. Details about the applied ECNI- 
methodology are given in appendix 1 in chapter 5.6.9. 
Briefly, chlordane analysis contained the following elements: 
• The extraction and clean-up method was identical with those for PCAs in biota 
and sediments. 
• ATI main chlordane compounds were present in the same fraction as PCAs. 
• Gas chromatographic separation was carried out on the same capillary as PCAs. 
• (7.s'-Hcptach lorcpox idc and oxy-chlordane co-eluted, but could be separated by mass 
spectrometry recording the not disturbed but less abundant masses m/z 388 (cis- 
heptachlorepoxide) and m/z 424 (oxy-chlordane). 
• Some unusual chlordane representatives such as MC5 and MC7 were also 
determined (for details, see Karlsson (1999) and Karlsson et al. (2000)) 
• Quantification was carried out by conventional ECNI according to the validated 
method described in Karlsson (1999) and Karlsson et al. (2000). 
• A method based on EI-MS/MS was also developed to check for possible 
systematic errors concerning quantification of sediments (for details, see appendix 
1, chapter 5.6.10). It had comparable detection limits except for cis- 
heptachlorepoxide, where detectability deteriorated by one order of magnitude. 
The same ECNI quantification technique was used on two different instruments for 
sediment analysis. No significant difference within the measuring uncertainty could be 
observed. The same was valid between ECNI and EI-MS/MS taken the very low 
concentrations in the pg/g dw range into account (see Table 16).