Matrix reference materials are included in the analysis as a quality control for extraction efficiency or performance of the assay. The matrix reference materials can also be applied for international standards, such as ISO 17025 or for the correction of the bioassay apparent recovery as required by the EU guidelines. Matrix reference materials are essential in the assessment of the accuracy and reliability of laboratory measurement processes. Our products are stable, homogeneous, well-characterized and are available for matrices such as e.g. feeding stuff, fish-oils, and egg powder. Certified values are determined by repetitive analysis in one or more analytical laboratories. On request, we can produce new materials for specific purposes.