Sequential and simultaneous determination of Pb, Ni, and Fe in dog and cat snacks using direct solids analysis by...

This study successfully optimised an analytical method for the concurrent determination of lead (Pb), nickel (Ni), and iron (Fe) in dog and cat treats using direct solids analysis and high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS). For Pb, Ni, and Fe detection, the wavelengths used were 217.001 nm, 232.003 nm, and 232.036 nm, respectively. The optimisation of the graphite furnace temperature programme established a pyrolysis temperature of 800 °C and atomisation temperatures of 1600 °C for Pb and 2500 °C for Ni and Fe. Spectral interferences were eliminated, and the limits of quantification (LoQ) for Pb, Ni, and Fe were determined to be 0.33 mg kg^-1, 0.40 mg kg^-1, and 1.4 mg kg^-1, respectively. The characteristic masses (m₀) obtained were 8.0 pg for Pb, 23 pg for Ni, and 1.82 ng for Fe. Analysis of the certified reference material (CRM) confirmed the method's trueness, with agreement ranging from 95.2 (±11.4)% to 120.4 (±30.2)%. The relative standard deviation (%RSD) values were below 24.2 % (n = 5), demonstrating the reliability of the analytical method. For dog and cat treat samples, Pb concentrations ranged from 0.9 (±0.2) mg kg^-1 to 2.9 (±0.1) mg kg^-1, while Ni concentrations varied between 0.5 (±0.1) mg kg^-1 to 2.5 (±0.9) mg kg^-1. The Fe concentration, in turn, spanned from 121 (±8) mg kg^-1 to 617 (±62) mg kg^-1. The analytical method effective for determining Pb, Ni, and Fe in pet treat samples through direct solids analysis and HR-CS GF AAS detection, making it suitable for routine analyses for quality control. The AGREE metric tools was evaluated, and the scores obtained was 0.73.