Proficiency Test on Mixed Xylenes finished

The full report can be downloaded (as .pdf-file). To download the report, please click the right mouse button and choose the "save as" option.

Download the report (iis11C09) of this Proficiency Test on Mixed Xylenes

For viewing the report you will need Adobe Acrobat Reader getacro.gif (712 bytes)


Summary of this proficiency test:

On 11 November 2011, the proficiency test on Mixed Xylenes (iis11C09) was finished. It started on 7 September 2011 (see message “Proficiency Test on Mixed Xylenes started” on this website) when the samples were distributed.

In this interlaboratory study 32 participants in 19 countries have participated.

The participants were asked to determine: Benzene, Toluene, p-Xylene, o-xylene, m-xylene, ethylbenzene, cumene, sum of c9 and heavier aromatics and sum of non-aromatics.

The proficiency test report summarises per test, the test results, the analytical methods reported by the participants and the z-scores calculated for each participant are tabulated. Also, for each test, the calculated summary (e.g. mean, standard deviation and reproducibility) is given.

In the report also an evaluation of the test results is given. Problems encountered in the analyses are mentioned and - where possible - suggestions for quality improvement are formulated. For each test a comparison is made between the results of the group of participants and the requirements given by the relevant standard (e.g. ISO, DIN, ASTM).