Determination of metallic elements in foods for enteral nutrition of chronic renal patients by atomic absorption spectrometry after extraction induced by emulsion breaking

Abstract This article describes the analysis of aluminum (Al), cadmium (Cd), copper (Cu), molybdenum (Mo), and lead (Pb) in foods for enteral nutrition of chronic renal patients by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GFAAS) after extraction induced by emulsion breaking. The following wavelengths were used for the detection of analytes 309.2713 nm for Al, 228.8018 nm for Cd, 324.7540 nm for Cu, 313.2594 nm for Mo, and 217.0005 nm for Pb. The detection limits for the methods were 0.022 mg kg−1 for Al, 0.0003 mg kg−1 for Cd, 0.001 mg kg−1 for Cu, 0.009 mg kg−1 for Mo, and 0.002 mg kg−1 for Pb. The precision ranged from 7.3% to 7.8%, 5.1% to 6.3%, 2.5% to 3.8%, 2.8% to 3.4%, and 6.2% to 7.3% for Al, Cd, Cu, Mo, and Pb, respectively. The accuracy of the method was evaluated through recovery tests, which ranged from 92.2% for Cd to 107.2% for Al. Cadmium concentrations in analyzed samples are below the limit allowed by Brazilian legislation (0.01 mg kg−1). However, two samples presented Pb concentration (samples 4 and 5) above the allowed limit (0.01 mg kg−1). Furthermore, all samples analyzed in this work showed relatively considerable quantities of Al (0.72–1.66 mg kg−1), and the concentrations of Cu (samples 3 and 4) and Mo (samples 1 and 5) were obtained were higher than those presented by the manufacturers. The proposed methods for the quantitative determination of the analytes of interest by HR-CS GFAAS after extraction induced by emulsion breaking in foods for enteral nutrition of chronic renal patients proved to be simple, fast, and efficient.