Determination of nickel in hydrogenated fats and selected chocolate bars in Czech Republic

Nickel is a metal that can be present in products containing hardened edible oils, possibly as leftover catalyst from the vegetable oil hardening process. Nickel may cause toxic effects including the promotion of cancer and contact allergy. In this work, nickel content was determined in hydrogenated vegetable fats and confectionery products, made with these fats, available on the Czech market using newly developed method combining microwave digestion and graphite furnace AAS. While concentrations of 0.086 ± 0.014 mg.kg−1 or less were found in hydrogenated vegetable fats, the Ni content in confectionery products was significantly higher, varying between 0.742 ± 0.066 and 3.141 ± 0.217 mg.kg−1. Based on an average consumer basket, daily intake of nickel from vegetable fats is at least twice as low as intake from confectionery products. Based on results, the levels of nickel in neither vegetable fats nor confectionery products, do not represent a significant health risk.