This European Standard is applicable to the preparation of representative test portions from the laboratory sample that has been taken according to the sampling plan (EN 14899), prior to physical and/or chemical analysis (e. g. preparation of eluates, extractions, digestion and/or analytical determinations) of solid (including monolithic material) and liquid samples and sludge. It is also applicable to the preparation of test portions from digests and eluates for the subsequent analyses. This European Standard is intended to find the correct sequence of operations and treatments to be applied to the laboratory sample in order to obtain suitable test portions in compliance with the specific requirements defined in the corresponding analytical procedures.