CEN/TR 17421:2019

This document gives guidance to those involved in designing, executing and evaluating interlaboratory comparison studies for multi-analyte methods of analysis, developed by CEN/TC 327 “Animal feeding stuffs: Methods of sampling and analysis” and its working groups. For the validation of multi-analyte methods their particularities must be considered which might necessitate deviations from the prescribed validation protocols. This study provides information whether the method is fit for its purpose and which performance can be expected in practical work while at the same time keeping the necessary effort for the study organizer and the participating laboratories minimal.Next to the abovementioned aspects regarding interlaboratory comparison studies, this document also gives guidance on the preceding steps, viz. in-house validation and preparation of the method protocol. Guidance is also given on the transferability of the method protocol and the familiarization with the method protocol through a training study, elements that – depending on the specific method – could be included in the design of the study.