Quantitative analysis and health risk assessment of selected heavy metals in pet food samples using ultrasound assisted hydrogen peroxide extraction followed by ICP-OES analysis

Abstract

There is a lack of information regarding the presence of heavy metals in feed ingredients for animals. Therefore, this study examines 10 feed samples collected from commercial pet food in South African market. The optimal working parameters for ultrasound assisted hydrogen peroxide extraction (UA-HPE) confirmed by multivariate optimization were sonication temperature at 80 °C for 60 min, sample mass of 0.1 g, and H₂O₂ concentration of 5 mol/L. The UA-HPE results demonstrated high accuracy of (>95%), reproducibility (≤1.9%), low method of detection limits (0.3498 and 0.49 μg/g), and strong linearity as confirmed by regression analysis. The environmental friendliness of the UA-HPE method was assessed using AGREEPrep metric tool that resulted with a score of 0.74. The concentration levels of Cd, Pb and As, ranged between 0.86 and 11.34, 4.50-11.45, and 2.61-12.5 μg/g, respectively greater than the standardized limits, whilst Cr, and Sn were below the limits of detection in all pet food. The health index calculations (HI > 1) revealed that the cat, dog, and horse feed pose health risk for animal consumption. Consequently, this study demonstrated a green, efficient, and cost-effective method for the analysis of animal feed with high accuracy.