Sulfonamides residues analysis: evaluation of results dispersion at maximum residual limit by the expanded uncertainty and 2002/657/EC decision limit approaches Original Research Article

It is impossible to determine whether an analytical procedure is suitable to the purposes without some knowledge of its uncertainty. Several approaches for its estimation have already been proposed in the past years. Discussion on the estimation of uncertainty of chemical measurement has also influenced the ISO 17025 which explicitly refers to the bottom-up approach. On the other hand, the European Commission Decision 2002/657/EC concerning the performance of methods and the interpretation of results in the official control of residues in products of animal origin imposes the determination of some new parameters, such as decision limit (CCα) which represents an index of results dispersion. This decision also indicates that official laboratories must be accredited according to ISO 17025. In this work, the bottom-up approach together with in-house validation data is applied for the evaluation of measurement uncertainty associated with residue determination of 10 sulfonamides in muscle and, at the same time, the decision limit was calculated following the 2002/657/EC criteria.