What makes the difference?

Direct access to experts
No matter if you want to discuss the latest ring test results or if you are looking for suitable reference materials or competence schemes, you will be able to contact us straightforward and hassle free. We appreciate sharing our thoughts with you and welcome feedback allowing us to constantly improve of our services.
You are the expert - you are invited to share your knowledge with us.
PROOF organises competence schemes for those analytical parameters, which are not available off-the shelf. For that purpose, we co-operate with experts in this field to develop well-founded and customised designs taking into consideration the complex analytical challenges of new analytes.
Paper doesn’t blush
We do not only tell you that we provide a high quality of test material – we are also able to prove the high-quality level. To do so, we publish as much information as possible to allow you to draw your own conclusions. The preparation of the material is described in detail. The spiked levels are published, and all homogeneity and stability data are provided. Applied methods for statistical evaluation are explained – in detail and comprehensively also for non-statisticians.
When statistics only are not enough
Unexpected upcoming analytical questions, non-standardised analytical methods or highly challenging parameters are in the focus of method ring tests offered by PROOF. An exchange of experiences – on an anonymous level – helps identifying shortcomings and improving analytical methods, in particular at early stages of method developments. Method details of the applied analytical method methods are summarised and also chromatograms are provided if helpful for the participants.
The challenges of PROOF competence schemes
Taking part in PROOF competence schemes can also be challenging. But challenges are necessary to improve. Benchmarking with highly quality driven laboratories by means of demanding parameters and complex products. Not only the comparability (z-score model) but also the trueness (recovery of the spiked levels) are criteria, which provide highly valuable information on the analytical performance of the participating laboratories. New approaches like non-homogenised test materials deliver additional information related to the quality of the applied sample preparation procedures.