Development and Validation of a Flame Atomic Absorption Spectrometry Method for Determining Cobalt in Mineral Premix for Animal Feed
DOI:
https://doi.org/10.33751/helium.v6i1.24Keywords:
animal feed, cobalt, flame atomic absorption spectrometry, method validation, mineral premixAbstract
Cobalt is an essential trace element in animal feed mineral premixes, and its concentration must be precisely controlled to ensure product quality and safety. A flame atomic absorption spectrometry (FAAS) method was developed and validated for the determination of cobalt in mineral premixes, with particular focus on optimizing the sample digestion procedure. The optimized digestion protocol combined dry ashing at 600 °C for 4 hours with wet digestion using concentrated HNO₃ and H₂SO₄ in a 3:1 ratio. Validation parameters included linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, repeatability, intermediate precision, and robustness. The calibration curve demonstrated strong linearity across the tested concentration range, with a correlation coefficient of 0.9996. The limit of detection (LOD) and limit of quantification (LOQ) were 0.0817 mg/L and 0.1366 mg/L, respectively. Recovery values ranged from 84.74% to 92.86%, and repeatability yielded a relative standard deviation (RSD) of 4.69%, meeting the acceptance criterion established by the Horwitz equation. Intermediate precision and robustness assessments revealed no significant differences between analysts or between furnace temperatures of 600 °C and 650 °C. These results indicate that the optimized digestion-FAAS method is reliable and suitable for routine cobalt determination in animal feed mineral premixes.
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