Liver plays a major role in metabolism and acts as a source of energy for the body by storing glycogen. Also, working with other systems and organs, it is responsible for several important functions such as storing iron, detoxifying harmful substances, maintaining the hormonal balance, and producing immune factors to fight infections. Cattle seemed to be the most sensitive animal species with respect to some metal toxicities resulting from ingestion of feed material. With the growing interest and investigation in the biological effects in recent years, it is important and necessary to develop accurate and comparable analytical methods for elements in bio-samples. It has, however, been 10 years since the tissue sample (bovine liver) of CCQM-K49 key comparison. Therefore, the IAWG has included the need for such a key comparison to maintain, expand and improve core capabilities, and to support specific CMCs claim in bio-sample analysis as well.