Cloud point extraction combined with high-performance liquid chromatography for speciation of chromium(III) and chromium(VI) in environmental sediment samples

Wang, Leilei; Wang, Jiaquan; Zheng, Zhixia; Xiao, Pu

doi:10.1016/j.jhazmat.2009.12.003

Cited by 117 publications

(30 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several procedures have been used for the preconcentration and separation of Cr(VI) from Cr(III) species, e.g. ion exchange, precipitation and co-precipitation, chelation, electrolysis, extraction, solid phase (Narin et al 2008) and cloud point extraction (Wang et al 2010a) and activated carbon adsorption (Gil et al 2006). Adsorption of heavy metals onto activated carbons is found to be the most effective for separation and enrichment of trace metals from aqueous solutions because of their extended surface area, microporous structure, high adsorption capacity and high degree of surface reactivity.…”

mentioning

confidence: 99%

Study of chromium(VI) adsorption onto modified activated carbons with respect to analytical application

Dobrowolski

Otto

2010

Adsorption

View full text Add to dashboard Cite

Two different types of modification of activated carbon, by treatment with concentrated solution of HNO 3 and outgassing treatment at high temperature, were studied in order to obtain the most effective adsorption of chromium(VI) ions from water solution. The basic parameters affecting the adsorption capacity of Cr(VI) ions on modified activated carbons were studied in details and the effect of modifications of activated carbons has been determined by studying the initial runs of adsorption isotherms. The obtained Cr(VI) adsorption isotherms were well fitted in the Freundlich equation. The reduction of Cr(VI) to Cr(III) and further ion exchange mechanism of adsorption onto oxidizing activated carbon and surface precipitation to Cr(OH) 3 in case of outgassing activated carbon were found as the main adsorption mechanisms of Cr(VI) ions onto modified activated carbons. Presence of chlorides and nitrates in studied adsorption system strongly decreased the adsorption ability of Cr(VI) onto outgassing activated carbon and mechanism of this behavior is proposed.

show abstract

mentioning

confidence: 99%

Study of chromium(VI) adsorption onto modified activated carbons with respect to analytical application

Dobrowolski

Otto

2010

Adsorption

View full text Add to dashboard Cite

show abstract

“…In addition, they are interesting complexing agents and have been used as reagents for [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] and even some f-elements-Tm(III), Th(IV) and U(VI) [31][32][33]. Besides, 2-naphthol coupled with 2-aminothiazole derivatives gives more sensitive reagents than phenol [34].…”

Section: Introductionmentioning

confidence: 99%

Synthesis, structural characterization and thermal studies of a novel reagent 1-[(5-benzyl-1,3-thiazol-2-yl)diazenyl]naphthalene-2-ol

Tupys

Kalembkiewicz

Ostapiuk

et al. 2016

J Therm Anal Calorim

View full text Add to dashboard Cite

A new thiazolylazo reagent 1-[(5-benzyl-1,3-thiazol-2-yl)diazenyl]naphthalene-2-ol has been synthesized via arylation of acrolein and further diazotization and diazocoupling with 2-naphthol. The chemical structure of the compound was confirmed by IR, NMR: 1 H, 13 C, COSY, HSQC and SALDI-MS spectral data. The DSC method was employed to determine the melting point and the enthalpy of fusion (T fus = 159.7°C and DH fus = 28.0 kJ mol -1 , respectively). Thermal stability and decomposition studies of the obtained azo dye were performed in air and nitrogen atmosphere using the TG technique. The evolved gases from the heated sample were registered on FTIR spectra. The decomposition of the azo dye in air atmosphere occurred in five consecutive stages. The pK a ionization constants of the substance were determined in ethanol-water mixture (1:1 v/v) by means of the spectroscopic method and were found to be equal to 0.41 for pK a1 and 9.59 for pK a2 . Using the spectrophotometric procedures, the methods for determination of trace amounts of toxic metallic ions with the new reagent were characterized and limits of detection were calculated.

show abstract

“…This step will also eliminate the matrix effect. Various conventional and recent miniaturized methods such as chemical co-precipitation (Krishna et al 2004;Uluozlu et al 2009) membrane extraction (Safari et al 2013), ion exchanging by resin (Narin et al 2008;Zou et al 2008;Sacmacı et al 2012), cloud point extraction (CPE) (Diniz and Tarley 2015;Wang et al 2010;Matos et al 2009), solid-phase extraction (SPE) (Jia et al 2016;Chen et al 2014;Wu et al 2012;Amin and Kassem 2012) and dispersive liquid-liquid micro-extraction (DLLME) (López-García et al 2013;Wen et al 2013;Yousefi and Shemirani 2013) have been developed for separation and enrichment of chromium species. Of these methods, SPE is the most widely employed procedure for the study of chromium speciation, particularly in water samples (Das et al 2012).…”

Section: Introductionmentioning

confidence: 99%

Fast, green and effective chromium bio-speciation using Sepia pharaonis endoskeleton nano-powder

Khedri

Ramezani

Rahbar

2016

Int. J. Environ. Sci. Technol.

View full text Add to dashboard Cite

The development of a fast, effective, simple and low-cost procedure for chromium speciation is an analytical challenge. In this work, a new and simple method for speciation and determination of chromium species in different matrices was developed. Sepia pharaonis endoskeleton nano-powder was used as an adsorbent for the dispersive micro-solid-phase extraction. Finally, the desorbed chromium was determined using a graphite furnace atomic absorption spectrometer. The experimental results showed that Cr(III) could be quantitatively extracted by the adsorbent, while Cr(VI) adsorption was negligible. Concentrated H 2 SO 4 and ethanol reduced Cr(VI)-Cr(III), and total chromium content was assessed as Cr(III). Then, the Cr(VI) concentration in the sample was calculated as the difference. The optimum conditions were obtained in terms of pH, adsorbent amount, contact time, and type, concentration and volume of eluent. Under the optimum conditions that involved the speciation of chromium ions from 25 mL of the water samples at pH 7.0 using 0.025 g of the adsorbent with contact time of 5 min, the method was validated in terms of linearity, precision and accuracy. The calibration curve was linear over the concentration range of 0.01-25.00 lg L -1 for Cr(III). The obtained limit of detection for the proposed method was 0.003 lg L -1 . The maximum adsorption capacity of the adsorbent was found to be 995.57 mg g -1 . The proposed method was validated by the speciation of Cr(III) and Cr(VI) in different real water and wastewater samples with satisfactory results.

show abstract

Cloud point extraction combined with high-performance liquid chromatography for speciation of chromium(III) and chromium(VI) in environmental sediment samples

Cited by 117 publications

References 23 publications

Study of chromium(VI) adsorption onto modified activated carbons with respect to analytical application

Study of chromium(VI) adsorption onto modified activated carbons with respect to analytical application

Synthesis, structural characterization and thermal studies of a novel reagent 1-[(5-benzyl-1,3-thiazol-2-yl)diazenyl]naphthalene-2-ol

Fast, green and effective chromium bio-speciation using Sepia pharaonis endoskeleton nano-powder

Contact Info

Product

Resources

About