Chromium redox speciation in food samples

Abstract

Chromium is an element with important biological characteristics, depending on its different species. Cr(III) is considered as essential; however, the Cr(VI) form is classified as carcinogenic. For this reason, speciation analysis in food samples is a very important question. The proposed data procedures for chromium redox speciation in the literature can be divided into those with the use of online hyphenated techniques and those where appropriate sample pretreatment is necessary. The strategies for nonchromatographic speciation are mainly based on selective liquid-liquid extraction procedures, coprecipitation, selective separation of chromium species using a solid phase extraction column, or complexation reactions. In this paper, the application of these strategies for determination of Cr(III) and Cr(VI) contents in common food samples (water, milk, tea infusion, bread, and beer) are presented and discussed. This survey is an attempt to cover the state of the art since 2012.

Analysis of Hazardous Elements in Children Toys: Multi-Elemental Determination by Chromatography and Spectrometry Methods

“…Trivalent chromium in yogurt and cheese samples ranges approximately from <13 to 255 ng/g. Most studies suggested the absence of hexavalent chromium in food samples like dairy and cereal products [ 37 ], chocolates, beverages, vegetables, fruits, eggs, meat and sea products [ 38 ], and flour [ 39 ], similar to the results from toy sample analyses obtained in this study.…”

Development and validation of a single run method based on species specific isotope dilution and HPLC-ICP-MS for simultaneous species interconversion correction and speciation analysis of Cr(III)/Cr(VI) in meat and dairy products

“…For the temperature optimization, the complexation of Cr(III) and Cr(VI) was carried out at 30, 50, 70 and 90 °C, respectively (duplicate analysis) using a reaction time of 25 min. It turned out that the complexation of both Cr(III) and Cr(VI) is incomplete at 30 °C while at 90 °C, consistent oxidation of Cr(III) to Cr(VI) occurs (not shown here), which is in agreement with other studies [6,43]. Quantitative derivatisation reactions of Cr(III)-EDTA (101%) and Cr(VI)-DPC (98%) was obtained at 70 °C.…”

“…Cr(III) is poorly soluble and relatively immobile in aqueous environments compared to Cr(VI), which is highly mobile, soluble and consequently, more bioavailable [4,5]. Cr(VI) has been recognized for several decades as being carcinogenic, whereas Cr(III) was for a long time considered as a beneficial element for the human health [6]. Nevertheless, the European Food Safety Authority (EFSA) stated relatively recently that there is no convincing evidence of beneficial effects of Cr(III) for healthy people [7].…”

“…Cr speciation analysis shifted relatively recently towards carrying out species separation by using high performance liquid chromatography (HPLC) before the on-line detection by atomic spectrometry, especially inductively coupled plasma mass spectrometry (ICP-MS) (on-line approaches) [6,[14][15][16][17]. Nevertheless, the on-line approaches are not per se capable to assess species interconversion during the extraction or HPLC separation steps.…”

Green Synthesis of Hierarchically Porous Alginate/ZIF‐8 Composite Beads for Water Treatment

“…Accompanied by the development of modern industry, water contamination problem occurs in daily life and seriously endangers the safety of human beings and other bio‐organisms. To eliminate the contaminants in water, a wide range of technologies have been developed, including ozonation, [1] microbial degradation, [2] photocatalytic degradation, [3,4] membrane filtration, [5] adsorption, [6–8] etc. Among these, adsorption is recognized as a preferable method because of its simple operation and economical properties [9] .…”