8th Needle/Leaf Interlaboratory Comparison Test 2005/2006

Wien

2006

33 S. + 74 S. Annex -Results

Monographie

3-901347-60-7

15015

128629

The results of the 8th Interlaboratory Comparison Test show generally a good analytical quality in foliar analysis. Some of the laboratories had to learn from their ringtest results, especially those with statistic outliers and/or results outside of the tolerable limits. A few laboratories must change their methods (e.g. dry ashing, nephelometry determination of sulphur) or check their methods with standard reference materials, ring test samples or pirmary standars. Calibration Problems of element analysers appear to be corrected. Most of the labs (90 %) are using control charts as a daily routine procedure. A trend in the use of analytical methods can be seen: - For C,N, (S) element-analyzers are becoming more and more important. - Acid digestion methods in closed systems in combination with ICP methods are very good for the determination of S, P, K, Ca, Mg, Fe, Zn, B and Cu. Flameless-AAS and ICP-MS methods should be used for analysing Cd, Pb and Cu (especially for low concentrations). An X-ray fluorescence analysis is the method of generate good results for S, P, Ca, Mg, K, Zn and Mn.