47 laboratories in 25 countries participated in the 24th Needle/Leaf Interlaboratory Test, but only 44 laboratories submitted their results in time.

The samples consisted of:

1. Spruce twigs (Austria) – same sample as for the 21st test (Sample 3 there)
2. Pine needles (Austria)
3. Beech leaves (Austria)
4. Spruce needles (Austria)

Special thank to all colleagues for collecting and preparing samples for this ringtest.

The following participating laboratories with a percentage of correct results below 80% have severe QC/QA-problems, a miscalculation of the results and/or methodical problems:

F07 (71.01%), F27 (75.81%), F22 (78.57%) and A85 (78.57%)

Some of the ICP-Forests laboratories failed and a re-qualification is obligatory for certain parameters (A45: K; A62: Mg; F07: S, B, As and Cr; F08: Cu; F13: C, F22: Ca, F27: K and F33: N). These ICP-Forests laboratories have to check and re-validate their methods or employ better applicable methods. FFCC offers old ringtest materials, if a reference material is needed for this purpose. Your NFC will be informed of your results too, in case you missed the qualification.

The laboratories A59 (N), A56 (S), A88 (Ca), A59 (C), A65 (Pb) and F07 (As) failed with the identical parameters in the last test(s). Therefore, their QC/QA-problem or their methodical problem is still not solved!

All interested laboratories are invited to take part in the re-qualification program up from now till 1st of September 2022.

Kind regards,
Michael Tatzber & Alfred Fürst

Download report (3,3 MB)