Minerals in cat and dog food

Brazilian scientists have measured the contents of 14 mineral elements in cat and dog food, to check their compliance with regulatory requirements. Rennan Geovanny Oliveira Araujo from the Federal University of Sergipe, and coresearchers, devised a sensitive method involving inductively coupled plasma-optical emission spectrometry which is outlined in Talanta.

After digesting the food with dilute nitric acid and hydrogen peroxide in a process optimised by two-level factorial design, the ICP-OES conditions were optimised by three-level factorial design. The resulting method provided limits of quantitation ranging from 0.03 µg/g for Cr to 87 µg/g for Ca and was validated with various NIST reference materials.

Cat and dog food bought locally in Aracaju City were found to contain the macronutrients Ca, K, Mg and P below the minimum levels established by the US Association of American Feed Control Officials (AAFCO) whereas levels of the micronutrients Cu, Fe, Mn and Zn agreed with AAFCO recommendations. Other elements like Al, Ba, Cd, S and Sr that were measured are not specified in the regulations.