|ISBN (pdf):||978-952-11-4561-2|| |
|Julkaisusarja ja numero:||Suomen ympäristökeskuksen raportteja 12/2016|| |
|Kustantaja:||Finnish Environment Institute|| |
|Saatavuus (pdf):||http://hdl.handle.net/10138/160804|| |
|Tekijät:||Riitta Koivikko; Jari Nuutinen; Markku Ilmakunnas
Proftest SYKE carried out the proficiency test (PT) for analysis of PCB compounds in soil in November-December 2015 (PCB 09/2015). Two types of samples were delivered to the participants, synthetic and soil samples. In total, 8 laboratories participated in the PT. The evaluation of the performance was based on the z scores, which were calculated using the standard deviation for proficiency assessment at 95 % confidence level. In this proficiency test 79 % of the data was regarded to be satisfactory when the standard deviation of 20 to 30 % from the assigned value was accepted. For the synthetic sample the calculated concentration and for the soil sample the mean of the results reported by the participants was chosen to be the assigned value. The uncertainty for the assigned value was estimated at the 95 % confidence interval and for calculated assigned values it was 0.5–1.2 %, for assigned values based on the mean it varied from 6.8 to 21.3 %.