Due to its strong analytically oriented type of research, the Toxicological Centre has developed an adequate quality control/quality assurance system. All analytical methods have been in-house optimized and validated using official guidelines and requirements. There is also an extensive participation in interlaboratory tests (where available) and the use of certified reference materials for assessing the accuracy of the methods.

POPs in human serum
The Toxicological Centre participates yearly in the interlaboratory tests organized by the Arctic Monitoring and Assessment Program (AMAP). In these ring tests, a large array of POPs, including PCBs, organochlorine pesticides and brominated flame retardants are measured in native and spiked human serum. Excellent results (values within 20% of the assigned values) were obtained in the last rounds (2011-2012) of these comparison exercises.
Bisphenol-A in urine
Several validation parameters (precision, recovery, limit of quantification) were determined and accuracy for the analysis of BPA in urine was evaluated by the participation to several interlaboratory comparison exercises organized in the frame of the EU DEMOCOPHES project. Excellent results (values within 1SD of the assigned values) were obtained in these comparison exercises. The chemical analysis of BPA required several precautions because external contamination with BPA from the environment and lab materials needs to be avoided.
The performance of the BPA analyses in urine has been evaluated also through the participation in the German EQUAS program (2011 and 2012) with excellent results (< 20% of consensus or assigned values).
Phthalate metabolites in urine
The performance of the analyses for phthalate metabolites in urine has been evaluated through the participation in the German EQUAS program (2011 and 2012) with good results (< 20-40 % of the consensus or assigned values).
Brominated flame retardants
In the past we have participated to a large number of ring tests for brominated flame retardants (PBDEs, HBCD and TBBPA) in abiotic and biotic matrices. These methods have shown very good performance and results in these ring tests were within 20% to the consensus or assigned values
Organophosphate flame retardants
Recently, we have participated to the 1st interlaboratory test for organophosphate flame retardants in abiotic (sediment and dust) and fish oil samples organized by IVM, VU Amsterdam. Excellent results with Z-scores within the limits of -2 to 2were obtained for the analytes included in the exercise (TCPP, TDCPP, TCEP, TPP, TBEP).
Illicit drugs in sewage
In 2011 and 2012, interlaboratory exercises were organized by the SCORE group for the measurement of drugs of abuse (cocaine, benzoylecgonine, amphetamine, methamphetamine, ecstasy, THC-COOH) in sewage; > 10 European laboratories participated. The performance of the Toxicological Centre was excellent, with Z-scores within the limits of -2 to 2.