Abstract: In this paper, the effects of sample particle size and sample volume on the results of WD-XRF measurement of elemental content in bovine liver powder samples were evaluated. A feasible, accurate, and measurably traceable method for the determination of inorganic elements in biological matrix samples by WD-XRF was established by comparing three different sample preparation additions. In addition, the method was validated for the K, Na, Ca, Mg, Cu, and Zn elements in the NIST standard reference materials 1577c, all elements showed good linearity, and the test results are within the uncertainty range, which proved that the method is accurate and reliable for the determination of inorganic elements in biological samples by the rapid WD-XRF method without matrix-matched standards.