Reduction of low concentration Cr(VI) in acid solutions

Archundia, C.; Bonato, Pierina Sueli; Rivera, José Francisco Lugo; Mascioli, L.C.; Collins, Kenneth E.

doi:10.1016/0048-9697(93)90077-j

Cited by 15 publications

(8 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Chromium in JSAC 0302-3 was prepared by adding potassium dichromate (i.e., Cr(VI)) in 0.1 mol l -1 nitric acid; 32 however, Cr(VI) was not detected in this test. Chromium(VI) was probably reduced to Cr(III) by preserving JSAC 0302-3 at pH 1, 33 because Cr(VI) is thermodynamically unstable in acidic regions. However, the analytical value of total Cr (Cr(III) + Cr(VI)) obtained in JSAC 0302-3 was in good agreement with the certified value.…”

Section: Validation Of Proposed Methodsmentioning

confidence: 99%

Determination of Cr(III) and Cr(VI) at Sub-ppb Levels in Water with Solid-Phase Extraction/Metal Furnace Atomic Absorption Spectrometry

et al. 2010

View full text Add to dashboard Cite

determined Cr(III) and Cr(VI) in river water and lake water with cation-and anion-exchange resin in batch experiments by ICP-AES. Sumida et al. 11,12 preconcentrated Cr(III) and Cr(VI) in tap water, river water, wastewater, and seawater with iminodiacetate chelating resin column by ICP-AES. Furusho et al. 13 developed an automated pretreatment system for the determination of Cr(III) and Cr(VI) in tap water, river water, and mineral drinking water with iminodiacetate chelating resin and synthesized chitosan resin columns by ICP-AES. In this way, the iminodiacetate chelating resin was often used for the speciation of Cr in water; however, the chelate-forming reaction 2010 © The Japan Society for Analytical Chemistry † To whom correspondence should be addressed. E-mail: tetsuo@meiji.ac.jp A simple method using solid-phase extraction combined with metal furnace atomic absorption spectrometry was developed for the determination of Cr(III) and Cr(VI) at sub-ppb levels in water. A 500-ml water sample was adjusted to pH 3 with nitric acid and then passed through an iminodiacetate extraction disk placed on a cation-exchange extraction disk at a flow rate of 20 -40 ml min -1 for concentrating Cr(III). The filtrate was adjusted to pH 10 with aqueous ammonia and then passed through an anion-exchange extraction disk at a flow rate of 2 ml min -1 for concentrating Cr(VI). The Cr(III) and Cr(VI) collected were eluted with 40 ml of 3 mol l -1 nitric acid for Cr(III) and 40 ml of 1 g l -1 diphenylcarbazide solution for Cr(VI). Each eluate was diluted to 50 ml with deionized water and injected into a U-type tungsten board on the metal furnace. The calibration curves of Cr(III) and Cr(VI) showed good linearity in the range of 0.1 -0.5 ng. The detection limits corresponding to three times the standard deviation (n = 5) of blank values were 8.1 pg for both Cr(III) and Cr(VI). The analytical value of total Cr (Cr(III) + Cr(VI)) in certified reference material of river water (JSAC 0302-3) was in good agreement with the reference value. The recovery test for 0.50 μg (1.00 μg l -1 ) of Cr(III) and Cr(VI) added to 500 ml of the water samples showed sufficient values (98.1 -106%), except for river water sampled downstream due to relatively higher CODMn value. The relative standard deviations (n = 5) were less than 5% for both Cr(III) and Cr(VI). Determination of Cr(III) and Cr(VI) at Sub-ppb Levels in

show abstract

Section: Validation Of Proposed Methodsmentioning

confidence: 99%

Determination of Cr(III) and Cr(VI) at Sub-ppb Levels in Water with Solid-Phase Extraction/Metal Furnace Atomic Absorption Spectrometry

et al. 2010

View full text Add to dashboard Cite

show abstract

“…Although the values in the present study are below the standards, Cr (VI) accumulates in living tissues, thereby becoming a bioaccumulation issue since Cr (VI) does not biologically decompose. Nor is it reduced at the pH of approximately 8 characterizing the study waterbody, although some authors have reported reduction (Archundia et al., ) at an acid pH in natural waters.…”

Section: Discussionmentioning

confidence: 89%

“…The Cr (VI) concentration decreases with distance towards the bay. (Archundia et al, 1993) at an acid pH in natural waters.…”

Section: Spatial Predictions (Kriging)mentioning

confidence: 99%

Spatial perspective of hexavalent chromium concentration in superficial waters of the Ciénaga de las Quintas Mangrove Swamp, Cartagena de Indias, Colombia

et al. 2018

View full text Add to dashboard Cite

A spatial characterization was undertaken to demonstrate the presence of hexavalent chromium (Cr (VI)) in surface waters (maximum depth of 0.5 m) in the Ciénaga de las Quintas mangrove swamp, located in the city of Cartagena de Indias, Colombia. This characterization was geostatistical in nature, an approach that is little used in such studies, although it offers two‐dimensional profiles of the concentration of relevant contaminants (hexavalent chromium in this case) with concentrations between 3 and 9.2 μg/L. Sampling was carried out systematically on a square grid with a cell size of one ha (100 m × 100 m). To corroborate the relationship between the sample positions and concentrations, the Euclidean distance matrices of each variable were calculated previous step for conducting the Mantel test, which indicated a positive correlation between the distance and concentration of hexavalent chromium (R = 0,1674: p value = 0.1275). The Moran Index was also calculated for Cr (VI). The experimental semivariogram (γ)was also calculated and fit to the exponential theoretical model, with a correlation coefficient of 99.4%. Using this analytical model of variance, predictions of Cr (VI) concentrations were made for unsampled locations, using the Kriging method with a new mesh side of only 10 m. This approach indicated the new mesh points exhibiting the higher concentrations coincided with locations in the swamp that receiving sewage effluents from the Bazurto public grocery market and the Chinatown neighbourhood. The Cr (VI) contamination was of anthropogenic origin because its concentration displays a gradient from the zone of human activities to the Cartagena de Indias bay.

show abstract

“…The reduction of Cr(VI) in many other acids, including the so-called "oxidizing acids", has also been reported [4][5][6][7][8][9][10][11][12][13][14]. Detailed studies of the reduction of low concentrations (up to 10 −3 mol L −1 ) of Cr(VI) with several different acids, including HNO 3 [9,10], HClO 4 [12], CF 3 SO 3 H [12], H 2 SO 4 [13], and HCl [13], have shown that the rate of reduction increases as the concentration of the *Author for correspondence (E-mail: chc@iqm.unicamp.br).…”

Section: Introductionmentioning

confidence: 99%

“…Detailed studies of the reduction of low concentrations (up to 10 −3 mol L −1 ) of Cr(VI) with several different acids, including HNO 3 [9,10], HClO 4 [12], CF 3 SO 3 H [12], H 2 SO 4 [13], and HCl [13], have shown that the rate of reduction increases as the concentration of the *Author for correspondence (E-mail: chc@iqm.unicamp.br). acid increases or as the concentration of the Cr(VI) decreases.…”

Section: Introductionmentioning

confidence: 99%

A radiochromatograpic study of the reaction of ⁵¹CrO₃ with hydrochloric acid

Pezzin¹,

Collins²

2001

Radiochimica Acta

Self Cite

View full text Add to dashboard Cite

The objective of the present work is to verify the reduction of CrO 3 in concentrated hydrochloric acid, using 51 Cr as a tracer. For the study, 51 CrO 3 was added to 37% HCl and maintained under agitation at 20 • C for specified time periods. Aliquots were diluted to approximately pH 2 and analyzed by open column cation and anion chromatography, either immediately or after storage for specified time periods. The separations, which were made by stepwise elution using HClO 4 and Ca(ClO 4 ) 2 solutions as eluents with fraction collection, followed by counting with a NaI(Tl) detector and a single channel analyzer, permitted construction of elution profiles whose peaks were identified by comparison with authentic samples. The results show that CrO 3 is reduced to Cr(III) in 37% HCl and that the initial identifiable product is [CrCl 3 (H 2 O) 3 ], a product which undergoes slow aquation at pH 2 to [Cr(H 2 O) 4 Cl 2 ] + , [Cr(H 2 O) 5 Cl] 2+ and [Cr(H 2 O) 6 ] 3+ .

show abstract

Reduction of low concentration Cr(VI) in acid solutions

Cited by 15 publications

References 7 publications

Determination of Cr(III) and Cr(VI) at Sub-ppb Levels in Water with Solid-Phase Extraction/Metal Furnace Atomic Absorption Spectrometry

Determination of Cr(III) and Cr(VI) at Sub-ppb Levels in Water with Solid-Phase Extraction/Metal Furnace Atomic Absorption Spectrometry

Spatial perspective of hexavalent chromium concentration in superficial waters of the Ciénaga de las Quintas Mangrove Swamp, Cartagena de Indias, Colombia

A radiochromatograpic study of the reaction of ⁵¹CrO₃ with hydrochloric acid

Contact Info

Product

Resources

About

Reduction of low concentration Cr(VI) in acid solutions

Cited by 15 publications

References 7 publications

Determination of Cr(III) and Cr(VI) at Sub-ppb Levels in Water with Solid-Phase Extraction/Metal Furnace Atomic Absorption Spectrometry

Determination of Cr(III) and Cr(VI) at Sub-ppb Levels in Water with Solid-Phase Extraction/Metal Furnace Atomic Absorption Spectrometry

Spatial perspective of hexavalent chromium concentration in superficial waters of the Ciénaga de las Quintas Mangrove Swamp, Cartagena de Indias, Colombia

A radiochromatograpic study of the reaction of 51CrO3 with hydrochloric acid

Contact Info

Product

Resources

About

A radiochromatograpic study of the reaction of ⁵¹CrO₃ with hydrochloric acid