Mechanistic insight into chromium(VI) reduction by oxalic acid in the presence of manganese(II)

Wróbel, Katarzyna; Escobosa, Alma Rosa Corrales; Ibarra, Alan Alexander González; Garcia, Manuel Mendez; Barrientos, Eunice Yáñez; Wróbel, Kazimierz

doi:10.1016/j.jhazmat.2015.06.066

Cited by 43 publications

(11 citation statements)

References 45 publications

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“…Since a better sensitivity (slope of the curve) quantitative response of the instrumental response (change in absorbance) to concentration of analyte was observed when the Cr (VI): Mn (II) ratio was 0.5:0.025, it was used as the best background ratio. This concentration ratio is consistence with previous results [20].…”

Section: Results and Discussion Methods Development And Optimizationsupporting

confidence: 93%

Spectrophotometric Determination of Oxalic Acid in Dietary Sources Through Catalytic Titration with Hexavalent Chromium

2019

FSQM

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Excess oxalic acid is thought to be a key factor of kidney stone formation in humans. Thus its level in food stuffs should be monitored. In this study, a new spectrophotometric titration method was developed for the determination of oxalic acid (OA) in dietary sources through reaction with hexavalent chromium in presence of Mn (II) as a catalyst. Cr (VI) was used as UV-active material and the determination of OA was based on the decrease in absorbance of the Cr (VI) solution as a result of its reaction with OA. Factors influencing the reduction of Cr (VI), including incubation time, solution pH and background concentration ratio have been optimized. The results showed that the amount of oxalic acid (mg/g) in vegetable samples of Ethiopian collared green (raw and cooked), cabbage (raw and cooked), lettuce (raw),beetroot (raw), pineapple (before ripe and fully ripe) and mango (before ripe and fully ripe) were 24.15 ± 0.565 and 12.05 ± 0.183, 16.72 ± 0.388 and 9.50 ± 0.424, 14.44 ± 0.183, 15.77 ± 0.175, 23.08 ± 0.212 and 18.31 ± 0.424, 6.75 ± 0.212 and 1.18 ± 0.169 respectively. Ethiopian collared green (Brassica oleraceavar. acephala) contained highest concentration of oxalate, but it was reduced by 50 % after boiling for ten minute. The level of oxalate content in the analyzed fruit samples was found to decrease with increasing growing stage or state of ripeness. All studied food samples contained relatively moderate amounts of total oxalate (< 25 mg/g dry weight) and are safe for human consumption especially when cooked or fully ripe. A very good correlation was observed when the results from the current method and standard method (HPLC) were compared. In conclusion, the current method can successfully be used for determination of OA in fruit and vegetable samples.

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Section: Results and Discussion Methods Development And Optimizationsupporting

confidence: 93%

Spectrophotometric Determination of Oxalic Acid in Dietary Sources Through Catalytic Titration with Hexavalent Chromium

2019

FSQM

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“…Cr(VI) in chromate or dichromate adsorbed on iron oxides could also be liberated due to reductive iron dissolution. However, part of the soluble Cr(VI) could then be reduced to form Cr 3+ in the presence of LMWOAs (Sun et al, 2009;Wrobel et al, 2015), depending on the reducing capacity of the organic acid. The relatively higher Cr in no-added biochar system than in the biochar-treated system for citric acid treatments indicates that part of the Cr was adsorbed by the biochar.…”

Section: -mentioning

confidence: 99%

Biochar immobilizes soil-borne arsenic but not cationic metals in the presence of low-molecular-weight organic acids

Alozie

Heaney

Lin

2018

Science of The Total Environment

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A batch experiment was conducted to examine the effects of biochar on the behaviour of soil-borne arsenic and metals that were mobilized by three low-molecular-weight organic acids. In the presence of citric acid, oxalic acid and malic acid at a molar concentration of 0.01M, the surface of biochar was protonated, which disfavours adsorption of the cationic metals released from the soil by organic acid-driven mobilization. In contrast, the oxyanionic As species were re-immobilized by the protonated biochar effectively. Biochar could also immobilize oxyanionic Cr species but not cationic Cr species. The addition of biochar increased the level of metals in the solution due to the release of the biochar-borne metals under attack by LMWOAs via cation exchange. Biochar could also have the potential to enhance reductive dissolution of iron and manganese oxides in the soil, leading to enhanced release of trace elements bound to these oxides. The findings obtained from this study have implications for evaluating the role of biochar in immobilizing trace elements in rhizosphere. Adsorption of cationic heavy metals on biochar in the presence of LMWOAs is unlikely to be a mechanism responsible for the impeded uptake of heavy metals by plants growing in heavy metal-contaminated soils.

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“…As demonstrated through the applications above, the technique can be coupled with a Multimode Sample Introduction System (MSIS) spray chamber for hydride generation that can operate in several modes, which should also be tested for performance for each application [ 178 ]. Finally, in other study fields, the combination of MP-AES and chromatographic techniques has also been exploited (see, as examples, [ 179 , 180 ]).…”

Section: Selected Instrumental Techniques and Their Applicationsmentioning

confidence: 99%

Selected Instrumental Techniques Applied in Food and Feed: Quality, Safety and Adulteration Analysis

Artavia

Cortés-Herrera

Granados-Chinchilla³

2021

Foods

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This review presents an overall glance at selected instrumental analytical techniques and methods used in food analysis, focusing on their primary food science research applications. The methods described represent approaches that have already been developed or are currently being implemented in our laboratories. Some techniques are widespread and well known and hence we will focus only in very specific examples, whilst the relatively less common techniques applied in food science are covered in a wider fashion. We made a particular emphasis on the works published on this topic in the last five years. When appropriate, we referred the reader to specialized reports highlighting each technique’s principle and focused on said technologies’ applications in the food analysis field. Each example forwarded will consider the advantages and limitations of the application. Certain study cases will typify that several of the techniques mentioned are used simultaneously to resolve an issue, support novel data, or gather further information from the food sample.

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Mechanistic insight into chromium(VI) reduction by oxalic acid in the presence of manganese(II)

Cited by 43 publications

References 45 publications

Spectrophotometric Determination of Oxalic Acid in Dietary Sources Through Catalytic Titration with Hexavalent Chromium

Spectrophotometric Determination of Oxalic Acid in Dietary Sources Through Catalytic Titration with Hexavalent Chromium

Biochar immobilizes soil-borne arsenic but not cationic metals in the presence of low-molecular-weight organic acids

Selected Instrumental Techniques Applied in Food and Feed: Quality, Safety and Adulteration Analysis

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