Forest Foliar Co-ordinating Centre (FFCC)
Re-Qualification Process after the 19th Needle and Leaf Interlaboratory Test 2016/2017
The laboratory must participate in each test for all mandatory parameters (N, S, P, Ca, Mg, K, C). It has been decided to qualify the results of each parameter (mandatory or optional) separately. If 50% or more of the results for this parameter for all the samples of the ringtest are within the tolerable limits, the laboratory is qualified. There is a special qualification procedure foreseen for results below the quantification limit.

Re-qualification is mandatory for ICP-Forests laboratories. There is no special qualification process forseen for other laboratories.

The qualification process starts with the ringtest participation. All participating ICP-Forests laboratories must analyze at least all the mandatory parameters. Finally, each laboratory gets a ringtest report and can download a qualification report. The laboratory passed for parameters highlighted in green and failed for parameters highlighted in red. For the red highlighted parameters a re-qualification is needed, if this parameter will be reported with monitoring files (*.FOM, *.LFM, *.GBM, *.GBO) to PCC! The ICP-Forests laboratories had to report key quality parameters like ringtest results, limits of quantification (LOQ) or control chart results per parameter with the monitoring data in a separate QA/QC file. Please, use the same information (ringtest number, pre-treatment code, determination code, ringtest result,...) like in your quality report for compiling your QA/QC-Files (*.FO_LQA, *.LT_LQA, *.GB_LQA).

In case of re-qualification:

The re-qualification process should start as soon as possible. The laboratory has to try to identify the reason for the bad results. The Quality Check paper of the ICP Forests working group on QA/QC in laboratories should be helpful (see: Also reference samples for method validation from IRMM, NIST or FFCC should be used.

If the problem is fixed a report should be sent to FFCC ( - please, download and use in any case the form for your re-qualification summary (download: *.xls File) and fill the green marked cells! All ringtest samples should be re-analyzed and with this report all printouts of the instruments, sample weights, dilution factors, and calibration factors and/or printouts should be submitted too. In case of a methodology problem a detail description of the used methodology is needed too (e.g. acid concentration in sample and standards, digestion parameters, standards, wavelength, linear working range, slit,...) and you had to highlight which part of the methodology you change now to find the correct results.

If the reason for the wrong results is a decimal error in the data submission or some other miscalculation (e.g. moisture correction), a short statement in your re-qualification paper (under point "Analytic reason") is enough.

If FFCC receives all needed papers your updated online qualification report can be downloaded. There is a deadline for re-qualification (1st of September) - please, submit your reports per email in minimum three weeks before this deadline to have time enough to answer possible requests. Please, use in all communications your lab code number!

In case you have not enough sample material left let me know this in time - FFCC will send additional ringtest sample material if available.

Download the form for the re-qualification report (*.xls File)
Get the last online QA/QC Report for your laboratory
08.01.16 | Fürst, A.
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