21 
Oil Spill identification - Round Robin 20045 
LVA ( http://www.lva.gov.lv/lea ) is a governmental institution 
subordinated to the Ministry of Environment of the Republic of Latvia. 
Their aim is to establish a seamless environmental information system 
to improve the environment and move towards sustainability. 
The samples have been analyzed by GC-FID and GC-MS. 
=> There is match between extract I and extract II. Extract I and extract II 
match to source I. 
2.5 The National Bureau of Investigation (NBI) 
Contact: Niina Viitala 
The National Bureau of Investigation http://www.poliisi.fi/nbi is one of 
the national units of the Finnish Police. The NBI is specialized in 
investigating and preventing serious, organized and international crime. 
At the national level, the NBI is responsible for criminal intelligence and 
identification of new types of crime. The NBI also develops techniques 
for criminal investigation and provides training in the mentioned 
subjects. 
The samples have been analyzed with GC-FID and GC-MS in SIM 
mode. The chemical analytical methodology is based on the CEN/TC BT 
Wl CSS27002.4 Oil spill identification - Waterborne petroleum and 
petroleum products- Parti, Date: 2003-11-31. 
=> Based on the visual inspection, the samples 1, 2 and 3 are the same kind of 
oil. There are some differences between the samples 1 and 2, but they are 
quite similar oils. The sample 4 is different from the samples 1 and 2. 
The conclusion is: 
Samples 1 and 2 are possible matches. 
Samples 1 and 3 are a positive match. 
Samples 1 and 4 are no match. 
Samples 2 and 3 are a possible match. 
Samples 2 and 4 are no match. 
Notes/remarks: 
The report starts with a triplicate analysis of the Sintef mixture (mixture 
of 4 oils produced for finding the right peaks). It is concluded that 
ratios are different, when calculated based on peak height or peak area. 
A calibration line based on height or area can be straight but the slope 
is different. Besides the height also the peak width increases slowly 
when increasing the concentration. So ratios to be compared can be 
based on height or area but should not be mixed. 
The st. dev should theoretically be the same but is in practice different. 
A difference in baseline drawing influences the st. dev of the area 
calculation to a greater extent, because the broadest part of a peak is at 
baseline level. On the other hand is the peak height calculation to a 
larger extent influenced by the scan rate and the stability of the