Determination of the Contents of Cr (III) and Cr (VI) in Man-Made Chromium-Enriched Foodstuffs by Graphite Furnace Atomic Absorption Spectrometry

 Abstract — A new application of graphite furnace atomic absorption spectrometry (GF-AAS) for the determination of the contents of Cr (III) and Cr (VI) in chromium -enriched foodstuffs was developed to evaluate the quality of commercial foodstuffs, including the nutrition and toxicity. Thenoyltrifluoracetonate (TTA) was used to form volatile complex with Cr (III), and separated from Cr (VI) as a vapor in the heated graphite furnace. The effects of sample digestion mode, pH, concentration of TTA, sonication time & temperature, and atomization conditions on the separation of Cr (III) and Cr (VI) were investigated. The limit of quantification (LOQ) of Cr (VI) was 0.003 mg/kg. The average recovery of Cr (VI) in chromium-enriched eggs was between 75% and 96%, and the relative standard deviation (RSD) was less than 11.5%. The developed method was also applied for a survey of selected chromium-enriched foodstuffs, and the contents of Cr (VI) in all samples were below its maximum contaminant level (MCL).