New matrix certified reference materials for the measurement of trace elements in swine and chicken compound feed

Abstract

New animal feed matrix certified reference materials (CRMs) were developed to measure Cu, Fe, Mn, and Zn trace elements in swine and chicken compound feed. The market-obtained raw feed materials were ground, blended, homogenized, bottled, and gamma-irradiated to prepare the CRM candidates. We then employed isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS), inductively coupled plasma optical emission spectroscopy (ICP-OES), flame atomic absorption spectroscopy (FAAS), and inductively coupled plasma mass spectrometry (ICP-MS) as reference methods in collaborative characterization program. The certified values and expanded uncertainties (at a confidence level of 95%, k = 2) of Cu, Fe, Mn, and Zn were assigned to be 60.48 ± 1.84, 367.0 ± 14.7, 159.1 ± 6.8, and 335.2 ± 7.7 μg/g in the swine compound feed CRM, respectively, and 39.53 ± 3.08, 332.0 ± 19.9, 111.3 ± 10.4, and 132.1 ± 7.8 μg/g in the chicken compound feed CRM, respectively. The homogeneity, short-term stability at 60˚C for 9 days, long-term stability at − 20˚C and room temperature for 18 months, and uncertainty evaluation were sufficiently studied. Thus, these two CRMs can be used for quality control and method validation to ensure the accurate and reliable measurements of swine and chicken feed for quality and safety monitoring.