ABSTRACT
Screening methods are used as a first-line approach to detect the presence of antibiotic residues in food of animal origin. The validation process guarantees that the method is fit-for-purpose, suited to regulatory requirements, and provides evidence of its performance. This article is focused on intra-laboratory validation. The first step in validation is characterisation of performance, and the second step is the validation itself with regard to pre-established criteria. The validation approaches can be absolute (a single method) or relative (comparison of methods), overall (combination of several characteristics in one) or criterion-by-criterion. Various approaches to validation, in the form of regulations, guidelines or standards, are presented and discussed to draw conclusions on their potential application for different residue screening methods, and to determine whether or not they reach the same conclusions. The approach by comparison of methods is not suitable for screening methods for antibiotic residues. The overall approaches, such as probability of detection (POD) and accuracy profile, are increasingly used in other fields of application. They may be of interest for screening methods for antibiotic residues. Finally, the criterion-by-criterion approach (Decision 2002/657/EC and of European guideline for the validation of screening methods), usually applied to the screening methods for antibiotic residues, introduced a major characteristic and an improvement in the validation, i.e. the detection capability (CCβ).
In conclusion, screening methods are constantly evolving, thanks to the development of new biosensors or liquid chromatography coupled to tandem-mass spectrometry (LC-MS/MS) methods. There have been clear changes in validation approaches these last 20 years. Continued progress is required and perspectives for future development of guidelines, regulations and standards for validation are presented here.
Acknowledgments
This work was conducted as part of the PhD thesis in biology I successfully defended in the year 2016. In this context, I wish to thank my supervisor, Dr. Michel Laurentie, ANSES Fougeres, for his expertise, advice, and kind assistance during this work. I thank him especially for making me aware of the overall approaches and for clarifications concerning sensitive statistical issues. I also thank the analysts I work with daily: Annie Rault and Celine Hédou, who performed several validation studies presented in this manuscript, thus allowing me to focus on writing my thesis. Thanks are also due to the head of the Antibiotic Biocide Residue Resistance (AB2R) unit, Christophe Soumet, ANSES Fougères and to Eric Verdon, head of the European Union Reference Laboratory (EU-RL) for Antimicrobial and Dye Residue Control in Food-Producing Animals.
Disclosure statement
No potential conflict of interest was reported by the author.