Chromium speciation in foodstuffs: A review

Abstract

Numerous critical reviews have evaluated exposure to toxic and carcinogenic hexavalent chromium (Cr(VI)) from a number of pathways; including workplace air, cement and packaging materials. The contribution of foodstuffs to dietary Cr(VI) has been increasingly under investigation, however no summary of this work has been carried out. The objective of this article is to review the last twenty years of chromium speciation research in foodstuffs. Alkaline extraction, used for chromium speciation in other solids, is the most widely-reported procedure. Previous measurement of Cr(VI) in foodstuffs is questionable due to the reducing power of organic matter and antioxidants, leading to the development of speciated isotope dilution mass spectrometry (SIDMS) techniques to monitor interconversions. Evaluation of the genotoxicity of trivalent chromium (Cr(III)), which acts through a different pathway to that of Cr(VI), requires reconsideration towards measurement of Cr(III), which is present at higher concentrations in foodstuffs following reduction of the more-bioavailable Cr(VI).

Chromium (III) and chromium (VI) as important players in the induction of genotoxicity – current view

“…These ions are released into the environment through various natural and anthropogenic activities and exist mainly in two forms: trivalent [Cr (III)] and hexavalent [Cr (VI)]. Hexavalent chromium compounds are extensively applied in diverse industries, while trivalent chromium salts are used as micronutrients and dietary supplements [4,5].…”

Pollution of Water Sources from Agricultural and Industrial Effluents: Special Attention to NO3ˉ, Cr(VI), and Cu(II)

“…Indeed, Cr(VI) is mainly analyzed, and various methods to prevent its reduction have been developed. There are two main groups of Cr speciation methods: off-and online techniques [82]. The off-line methods use pretreatment techniques for separation and concentration of specific Cr species (in the samples) before its insertion into detection instruments.…”

Critical review on microbial fuel cells for concomitant reduction of hexavalent chromium and bioelectricity generation

“…The US Environmental Protection Agency and the European Union have assigned the maximum permitted discharge level of total chromium into water bodies to below 0.05 mg L −1 . Chromium is present in oxidation states ranging from Cr 2+ to Cr 6+ , but the most stable and common forms are trivalent chromium (Cr(III)) and hexavalent chromium (Cr(VI)), which have varying chemical properties and impinge organisms in different ways . Cr(III) plays a crucial role in the maintenance of glucose, cholesterol and triglyceride levels and is an integral trace element for human and animal health.…”

“…7 Chromium is present in oxidation states ranging from Cr 2+ to Cr 6+ , but the most stable and common forms are trivalent chromium (Cr(III)) and hexavalent chromium (Cr(VI)), which have varying chemical properties and impinge organisms in different ways. 4,8 Cr(III) plays a crucial role in the maintenance of glucose, cholesterol and triglyceride levels and is an integral trace element for human and animal health. In contrast, Cr(VI) is considered the most deleterious form of chromium owing to its greater water solubility and bioavailability than Cr(III).…”