Low pressure closed system applied to sample preparation of instant soups for elemental determination by MIP OES

Abstract

The increased consumption of ultra-processed foods has made the assessment of the presence of essential and/or potentially toxic elements more relevant. This work proposes the application and evaluation of a closed low pressure system for the acidic decomposition of instant soup samples and determination of Ba, Ca, Cd, Cr, Cu, Fe, Hg, K, Mg, Mn, Pb and Zn by microwave-induced plasma optical emission spectrometry (MIP OES). The accuracy of the standard method was verified using certified reference materials and the values obtained were consistent with the certified values according to Student's t-test at 95% confidence. Addition and recovery tests were also performed, and the results varied from 86 to 119%. The concentrations varied of the 1.29 to 3.78 mg kg−1 for Ba; 414 to 6221 mg kg−1 for Ca; 0.40 to 1.13 mg kg−1 for Cr; < 0.006 to 4.16 mg kg−1 for Cu; 5.56 to 115 mg kg−1 for Fe; 48 to 444 mg kg−1 for K; 185 to 654 mg kg−1 for Mg; 0.11 to 8.39 mg kg−1 for Mn; 0.94 to 7.48 mg kg−1 for Pb and 3.01 to 42.7 mg kg−1 for Zn. For the Cd and Hg analytes, the concentration results were below their detection limits. The potentially toxic elements in this study showed concentrations below the established limit of daily intake, not offering risks to the consumer's health. As for the essential elements for the body, the concentrations were lower than those recommended for daily intake.