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Oil Spill identification - Round Robin 20045 
detector, because only one scan or data point is used. E.g. in Fig 1 of 
the report of NBI the peak of BaF is slightly cut off. As a result the top 
of the peak is slightly higher than analyzed. This is caused by the 
limited scan speed of a mass spectrometer compared to the peak width. 
It is stated that the CEN-method is used to compare the samples, but 
actually mass chromatograms were only visually compared. 
2.6 The National Environmental Research Institute (NERI) 
Contacts: Asger Hansen 
NERI http://www.dmu.dk/lnternational/ is an independent research 
institute under the Danish Ministry of the Environment. NERI 
undertakes scientific consultancy work, monitoring of nature and the 
environment as well as applied and strategic research. NERI's task is to 
establish a scientific foundation for environmental policy decisions. 
The RR-samples were analyzed in duplicate with GC-FID and GC-MS. 
A VG 70S-250 double-sector instrument operated in single-ion 
recording (SIR) mode was used for the GC-MS analyses. 
=> Based on visual comparison of GC-FID chromatograms and GC-MS ion 
fragmentograms of spill and PRP source samples, the generation and direct 
and statistical comparison of 45 diagnostic compound ratios for each sample 
based on the repeatability limit, the following conclusions can be made: 
Spill-I (Extract-I) contains a mixture of fuel and lubricating (motor) oil, that 
has been weathered to some degree affecting compounds below nC20. This 
sample match the PRP Source-I sample almost perfectly, and hence these two 
sample are identical beyond reasonable doubt. The spill sample does not 
match the PRP Source-II sample, and the two samples are non-identical. 
Spill-II (extract-II) also contains a mixture of fuel and lubricating (motor) oil 
like Spill-I. It has been weathered and degraded to higher degree than Spill-I, 
but these two spill samples are probably identical, although this has not been 
directly tested. Spill-II sample match the PRP source-I sample closely but not 
perfectly, and the two samples are therefore probably identical. Spill-II does 
not match Source-II, and the two samples are non-identical. 
2.7 Netherlands Forensic Institute (NFI) 
Contact: Rene de Bruyn 
The Netherlands Forensic Institute www.forensischinstituut.nl analyses 
oil samples in cases of arson (e.g. gasoline and kerosene) and 
environmental contaminations. 
The RR-samples were analyzed in duplicate with GC-MS. In full scan 
mode, at a concentration of 1 g/l dissolved in petroleum ether for 
screening and at the same concentration for SIM analysis of PAH's and 
terpanes. The method uses 14 specifically formulated PAH ratios and 7