Forest Foliar Co-ordinating Centre (FFCC)
10th Needle/Leaf Interlaboratory Comparison Test - 2007/2008
54 European laboratories from 29 countries participated in this test - 52 were sending 10912 results. 
4 samples were sent:
  • Sample 1 (Spruce needles/Austria)
  • Sample 2 (Spruce needles/Austria)
  • Sample 3 (Ash leaves /Austria)
  • Sample 4 (Ash leaves/Belgium) is indentical with sample 4 from the 7th test
Lower tolerable limits for the mandatory parameters S to ± 15% and for P, Ca, Mg and K to ± 10% were fixed at the Expert Panel Meeting in Madrid in April 2007, because of the improvement of the data quality in most of the laboratories. The 10th Interlaboratory Test was evaluated with these stricter limits.
The results show generally a good analytical quality in foliar analysis. Especially the results for N and C are really good and are better than those in the previous tests.
The results of the mandatory parameters S, P, Ca, Mg and K are not as good as in former tests, depending partly on of the stricter tolerable limits. But for S, Ca and K there are probably other methodical reasons for the increase of non-tolerable results.
The results for the optional parameters Fe, Cu, Pb are better than those of the 9th Interlaboratory Test.

Some of the laboratories had to learn from their ringtest results and had to improve their quality. They had to make a revision of their method, especially those with statistical outliers and/or a considerable number of results (more than 20%) outside of the tolerable limits (especially the laboratories 01, 05, 13, 15, 19, 30, 36, 76, 78 and 79).

Results of the 27 "Level II - laboratories"

The complete report of the 10th Needle/Leaf Interlaboratory Comparison Test can be downloaded here:

Download pdf-File (1,9 MB)
07.05.13 | Fürst, A.
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