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).
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
|Year||Short Name||Topic||Final Report|
|2021||NIIM1021||Nitroimidazoles in plasma and milk|
|2021||STRD0521||Precision and accuracy in the analysis of standard solutions||Preliminary Report (FIS-VL)|
|2020||NSAI1120||NSAIDs in bovine and equine muscle||Final Report (FIS-VL)|
|2020||BETA0320||Beta-agonists in bovine hair||Final Report (FIS-VL)|
|2019||COCC1019||Coccidiostats in chicken egg||Final Report (FIS-VL)|
|2019||AVER0619||Avermectins and nitroimidazoles in fish muscle||Final Report (FIS-VL)|
|2018||MSM1118||Multi-screening of pharmaceutically active drugs in bovine milk||Final Report (FIS-VL)|
|2017||COCC1117||Coccidiostats in sheep and goat muscle||Final Report (FIS-VL)|
|2017||NSAI0917||NSAIDs in bovine milk||Final Report (FIS-VL)|
|2016||BETA1116||Beta-agonists in bovine and porcine liver||Final Report (FIS-VL)|
|2016||NIIM0716||Nitroimidazoles in chicken egg||Final Report (FIS-VL)|
|2015||NSAI1015||NSAIDs in bovine milk||Final Report (FIS-VL)|
|2015||BETA0715||Beta-agonists in bovine urine||Final Report (FIS-VL)|
|2014||ANTH1014||Antihelmintics in bovine milk||Final Report (FIS-VL)|
|2013||COCC1013||Coccidiostats in poultry liver, muscle, and egg||Final Report (FIS-VL)|
|2012||BETA1012||Beta-agonists in bovine hair||Final Report (FIS-VL)|
|2011||NIIM0511||Nitroimidazoles in porcine plasma||Final Report (FIS-VL)|
|2010||NSAI0910||NSAIDs in bovine milk||Final Report (FIS-VL)|
|2009||ANTH0909||Antihelmintics in bovine muscle||Final Report (FIS-VL)|
|2008||ANTH0408||Antihelmintics in bovine milk||Final Report (FIS-VL)|
|2007||NIIM0907||Nitroimidazoles in chicken egg||Final Report (FIS-VL)|
|2006||COCC0606||Coccidiostats in chicken egg||Final Report (FIS-VL)|
|2005||AVER0705||Avermectins in bovine milk||Final Report (FIS-VL)|
|2004||BETA0604||Beta-agonists in urine and liver||Final Report (FIS-VL)|
|2003||COCC0603||Coccidiostats in chicken egg||Final Report (FIS-VL)|
|2002||NSAI0502||NSAIDs in bovine plasma||Final Report (FIS-VL)|
|2001||NIIM0301||Nitroimidazoles in muscle||Final Report (FIS-VL)|
|2000||BETA0600||Beta-agonists in bovine retina||Final Report (FIS-VL)|
|1999||NIIM0699||Nitroimidazoles in turkey muscle||Final Report (FIS-VL)|
|1997||BETA1197||Beta-agonist Interlaboratory Study|
|1996||BETA0596||Beta-agonist Interlaboratory Study|