In this study a new method for chromium speciation in water using solid phase extraction coupled to a flow injection system and flame atomic absorption spectrometry was developed. The adsorption behavior of Cr(III) and Cr(VI) on Nb2O5-SiO2 allowed the selective separation of Cr(III) from Cr(VI) in the pH range of 6-9. Thus, a method for Cr(III) preconcentration and extraction using Nb2O5-SiO2 was developed. Total chromium was determined after the reduction of Cr(VI) to Cr(III) using sodium sulfite in acidic medium. The operational variables of the preconcentration and reduction procedures were optimized through full factorial and Doehlert designs. The limit of detection for Cr(III) was 0.34microgL(-1) and the precision was below 4.6%. Results for recovery tests using different environmental samples were between 90 and 105%. Certified reference materials (NIST 1640 and NIST 1643e) were analyzed in order to check the accuracy of the proposed method, and the results were in agreement with the certified values.
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http://dx.doi.org/10.1016/j.jhazmat.2008.03.117 | DOI Listing |
J Environ Manage
January 2025
Department of Occupational and Environmental Health, Xiangya School of Public Health, Central South University, Changsha, China. Electronic address:
Traditionally, abiotic factors such as pH, temperature, and initial Cr(VI) concentration have been undoubtedly recognized as the external driving forces that dramatically affect the microbial-mediated remediation of Cr(VI) pollutants. However, concentrating on whether and how the biological behaviors and metabolic activities drive the microbial-mediated Cr(VI) detoxification is a study-worthy but little-known issue. In this study, Leucobacter chromiireducens CD49 isolated from heavy-metal-contaminated soil was identified to tolerate 8000.
View Article and Find Full Text PDFInorg Chem
January 2025
Department of Environmental Science and Engineering, Fuzhou University, Minhou, Fujian 350108, China.
Environmental concerns are driving the development of eco-friendly and effective methods for contaminant monitoring and remediation. In this study, a lanthanide porphyrin-based MOF with dual fluorescence sensing and photocatalytic properties was synthesized and applied for the detection and combined removal of Cr(VI) and ciprofloxacin (CIP). Using different excitation wavelengths, the material exhibited selective detection of Cr(VI) via fluorescence quenching and CIP through fluorescence enhancement.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
Shenzhen Research Institute of Xiamen University, Shenzhen 518000, China; College of the Environment and Ecology, Xiamen University, Xiamen 361005, China; Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies, Xiamen 361005, China. Electronic address:
Due to the distinct difference in chemical properties, analysis of organic pollutants and heavy metals generally employs different sample preparation and measurement techniques, resulting in low analytical efficiency and high cost. To this end, a strategy for the co-extraction and then simultaneous quantification of organic pollutants and heavy metals was proposed by the on-line hyphenation of magnetic field-assisted in-tube solid phase microextraction (MA/IT-SPME) and HPLC technique. Simultaneous analysis of triazoles and chromium species were adopted as paradigm to demonstrate the feasibility of the proposed strategy.
View Article and Find Full Text PDFSci Total Environ
February 2025
Department of Chemistry, Physics, Environmental and Soil Sciences, University of Lleida - AGROTECNIO-CERCA Center, Rovira Roure 191, 25198 Lleida, Spain.
There is limited research on the influence of environmental variables on the interactions of biodegradable microplastics with chromium. This study reports the results of adsorption experiments with Cr and poly(lactic acid) (PLA) in synthetic aqueous solutions. It addresses the influence of the initial oxidation state, Cr(III) or Cr(VI), the effects of UV irradiation and the presence of organic matter.
View Article and Find Full Text PDFEnviron Pollut
January 2025
Xi'an Center of Mineral Resources Survey, China Geological Survey, Xi'an, China.
Understanding the geochemical mechanisms governing hexavalent chromium (Cr(VI)) in groundwater is essential for mitigating health risks. However, the processes driving Cr(VI) accumulation and migration in loess regions remain insufficiently understood. This study investigated the occurrence, release, and migration mechanisms of Cr(VI) across different groundwater environmental units (GEUs) in the south-central Loess Plateau, China.
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