Development Of The Certified Reference Material Of Chromium In Lyophilized Bovine Blood

Background Hexavalent chromium compounds are serious industrial toxins and environmental pollutants. Hexavalent chromium would cause oxidative stress and induce related multiple system health effects or cancer after absorption. Blood chromium content is one of the important biological markers of chromium, reference materials are needed in order to improve the quality of blood chromium detection. However, there is no domestic manufacture producing such reference materials in China at present, the supply of the reference materials rely on foreign manufactures. Therefore, the development of blood chromium certified reference materials is very necessary.Objectives To develop the component analysis certified reference materials of chromium in lyophilized bovine blood according to the national certified reference material requirements.Methods Bovine blood was chosen as the matrix, and trivalent chromium and hexavalent chromium were spiked into it after it was filtered. The spiked blood were homogenized, dispensed, lyophilized, then were stored at the -20 ?. The minimal sampling weight of the materials, homogeneity test and stability inspection were conducted, the certified values and evalution of uncertainty werebased on analysis made by five independent laboratories, using inductively coupled plasma-mass spectrometric method and graphite furnace atomic absorption spectrometric method.Results Two levels of lyophilized bovine blood chromium reference materials were developed, approximatly 1000 bottles each level. The minimal sampling weight of the materials is 0.1mL, the homogeneity of the reference material was good. The results of homogeneity evaluation shows that the F are 1.76 and 0.74, the difference within bottles and between bottles was insignificant(P>0.05). The lyophilized bovine blood samples were stored at -20?, and the linear regression based on the stability inspection of 6 months showed that the linear trend was insignificant(.P>0.05). The samples can be stored formore than 6 months at -20 ?. The dissolved samples can be stabile for seven days at -4? and -20?. Our samples were stabile for fourteen days at room temperature. The certified values were as follows:low level is (4.06±0.50) ?g/L, high level is(26.24±1.74) ?g/L.Conclusion The certified reference material of chromium in lyophilized bovine blood in this research reached the national certified reference material requirements. As chromium carrier of traceability in the bovine blood, the reference material can be applied to the quality control and the method validation of chromium detection in whole blood.