Proficiency Tests

Residue analysis is a field of analytical chemistry which strongly relies on the confidence which can be attributed to measurement results. Consequently, no result in residue analysis ever stands isolated. Every analysis is rather approached as embedded into quality control measures whose purpose is inter alia the control of environmental influences, the demonstration of adequate performance of methods, as well as the provision of clear documentation of all involved processes. It is through these quality control measures that reliability in analytical results can be established.
Apart from internal quality control measures which guarantee the validity of results on a day-to-day basis, it is also necessary to verify method performance against external criteria. One method to accomplish that is through the participation in proficiency tests, which is also a requirement under ISO 17025. In contrast to internal quality control measures, proficiency tests may offer additional information on trueness and bias and they give the participants feedback on their performance in comparison to other laboratories.
The EURL Berlin also values proficiency tests because they may provide information on the performance of different analytical approaches and can be used as a tool for the assessment of measures towards the harmonisation of laboratory performance (e.g. collaborative trials).

Legal requirements

In accordance with Art. 94 of Regulation (EC) No 2017/625 of the European Parliament and of the Council European Union European Union Reference Laboratories are required to coordinate the application of suitable methods by the Reference Laboratories i.a. through organisation of proficiency tests. The National Reference Laboratories on their part are required to participate in proficiency tests organised by the European Reference Laboratories (EURL) (Art. 101).

Common Proficiency Testing Protocol

In 2020, the EURLs Wageningen and Berlin published a common protocol for the conduction of proficiency tests and the management of underperformance. The document outlines the approach of both EURLs to proficiency tests they may conduct in their role as EURL within the NRL network and harmonises the criteria for performance assessment.

Overview of EURL Berlin Proficiency Tests

YearShort NameTopicFinal Report
2021NIIM1021Nitroimidazoles in plasma and milk
2021STRD0521Precision and accuracy in the analysis of standard solutionsPreliminary Report (FIS-VL)
2020NSAI1120NSAIDs in bovine and equine muscleFinal Report (FIS-VL)
2020BETA0320Beta-agonists in bovine hairFinal Report (FIS-VL)
2019COCC1019Coccidiostats in chicken eggFinal Report (FIS-VL)
2019AVER0619Avermectins and nitroimidazoles in fish muscleFinal Report (FIS-VL)
2018MSM1118Multi-screening of pharmaceutically active drugs in bovine milkFinal Report (FIS-VL)
2017COCC1117Coccidiostats in sheep and goat muscleFinal Report (FIS-VL)
2017NSAI0917NSAIDs in bovine milkFinal Report (FIS-VL)
2016BETA1116Beta-agonists in bovine and porcine liverFinal Report (FIS-VL)
2016NIIM0716Nitroimidazoles in chicken eggFinal Report (FIS-VL)
2015NSAI1015NSAIDs in bovine milkFinal Report (FIS-VL)
2015BETA0715Beta-agonists in bovine urineFinal Report (FIS-VL)
2014ANTH1014Antihelmintics in bovine milkFinal Report (FIS-VL)
2013COCC1013Coccidiostats in poultry liver, muscle, and eggFinal Report (FIS-VL)
2012BETA1012Beta-agonists in bovine hairFinal Report (FIS-VL)
2011NIIM0511Nitroimidazoles in porcine plasmaFinal Report (FIS-VL)
2010NSAI0910NSAIDs in bovine milkFinal Report (FIS-VL)
2009ANTH0909Antihelmintics in bovine muscleFinal Report (FIS-VL)
2008ANTH0408Antihelmintics in bovine milkFinal Report (FIS-VL)
2007NIIM0907Nitroimidazoles in chicken eggFinal Report (FIS-VL)
2006COCC0606Coccidiostats in chicken eggFinal Report (FIS-VL)
2005AVER0705Avermectins in bovine milkFinal Report (FIS-VL)
2004BETA0604Beta-agonists in urine and liverFinal Report (FIS-VL)
2003COCC0603Coccidiostats in chicken eggFinal Report (FIS-VL)
2002NSAI0502NSAIDs in bovine plasmaFinal Report (FIS-VL)
2001NIIM0301Nitroimidazoles in muscleFinal Report (FIS-VL)
2000BETA0600Beta-agonists in bovine retinaFinal Report (FIS-VL)
1999NIIM0699Nitroimidazoles in turkey muscleFinal Report (FIS-VL)
1997BETA1197Beta-agonist Interlaboratory Study
1996BETA0596Beta-agonist Interlaboratory Study