Forest Foliar Co-ordinating Centre (FFCC)
17th Needle/Leaf Interlaboratory Comparison Test - 2014/2015
54 laboratories in 25 countries participated in the 17th Needle/Leaf Interlaboratory Test. The following test samples were submitted to the participants:

1. Spruce needles - Picea abies (Croatia)
2. Spruce needles - Picea abies (Germany)
3. Pine needles – Pinus nigra (Austria) - same sample like in the 15th Test (Sample 1)
4. Sycamore maple leaves - Acer pseudoplatanus (Switzerland)

Sample 1 was collected from Tamara Jakovljevic and her employees in Croatia. Sample 2 was collected from Frank Symossek and his employees in Germany. Sample 3 was collected in Arnoldstein in Austria, and Sample 4 was collected from Peter Waldner and his employees in Switzerland. Special thank to all colleagues for collecting and preparing samples for this ringtest.

The following participating laboratories with a lower percentage of correct results (less than 80%) have bigger QC/QA-problems in their laboratory and/or with their method:

A43 (78.6%), A71 (78.6%), F26 (78.6%), F06 (76.6%), F21 (70.8%), F11 (70.2%), A53 (66.7%), F29 (58.8%), A59 (58.3%), F24 (57.1%) and A83 (34.0%).

Figure 1: 17th Interlaboratory Comparison Test - Percentage of correct results

An interesting point is that most of these laboratories (say that they) have control charts, but they don’t use it for adjusting their method. Otherwise they must detect these sometimes huge deviations from the target value!

All of these laboratories had to check and validate their method or select a new (better) method. If reference material is needed - FFCC can offer some ringtest material.

All interested laboratories are invited to take part in the re-qualification program.
A clear methodical recommendation to ICP-AES can be given and, where ICP-AES is not sensitive enough, ICP-AES with ultrasonic nebulizer, ICP-MS or Flameless AAS should be used. For nitrogen and carbon, element analyzers are the best choice, if a correct calibration is performed.

Download final report (6.4 MB)
15.01.15 | Fürst, A.
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