Specific Extraction of Chromium as Tetrabutylammonium-Chromate and Spectrophotometric Determination by Diphenylcarbazide: Speciation of Chromium in Effluent Streams
Open Access
- 3 May 2003
- journal article
- Published by Springer Science and Business Media LLC in Analytical Sciences
- Vol. 19 (5), 705-708
- https://doi.org/10.2116/analsci.19.705
Abstract
A very specific, selective, simple and inexpensive procedure was developed for the speciation of CrVI and CrIII. This method is based on the quantitative extraction of chromate and CrIII (previously oxidized to CrVI) as a tetrabutylammonium-chromate ion-pair in methyl isobutyl ketone (MIBK), and then back extraction and preconcentration with an acidic diphenylcarbazide (DPC) solution. Back extraction was applied to achieve further preconcentration by a final factor of 20. The CrVI-DPC complex was determined in back-extract by a spectrophotometer at 548 nm. Under these extraction conditions, most of the probable concomitant cations and anions remained in the first inorganic phase. The calibration curve was linear up to 0.14 μg L-1 of CrVI with a detection limit of 2.22 ng L-1. The developed procedure was found to be suitable for the determination of the CrVI and CrIII species in various natural water samples with a relative standard deviation of better than 1.6%. The method was successfully applied to the speciation of chromium in spiked natural water samples, and also samples of effluent from a leather treatment plant.Keywords
This publication has 14 references indexed in Scilit:
- Speciation of chromium by solid-phase extraction coupled to reversed-phase liquid chromatography with UV detectionAnalytica Chimica Acta, 1998
- Selective Determination of Cr(VI) by a Self-Assembled Monolayer-Based ElectrodeAnalytical Chemistry, 1997
- Simultaneous determination of chromium(III) and chromium(VI) in aqueous solutions by ion chromatography and chemiluminescence detectionThe Analyst, 1992
- Selective determination of trace level chromium(III) by ion-pair reversed-phase high-performance liquid chromatography based on the color formation with 4-(2-pyridylazo)resorcinol in the presence of triethanolamineAnalytical Chemistry, 1985
- Sequential spectrophotometric determination of chromium(III) and chromium(VI) using flow injection analysisThe Analyst, 1985
- Metal speciation by flow-injection analysisTalanta, 1983
- Determination of traces of chromium(vi) as a thiosemi-carbazide complex by solvent extraction and atomic absorption spectrometryAnalytica Chimica Acta, 1980
- The determination of chromium species in natural watersAnalytica Chimica Acta, 1978
- Analysis for chromium traces in natural waters: Preconcentration of chromate from p.p.b. levels in aqueous solutions by ion exchangeAnalytica Chimica Acta, 1974
- The extraction-spectrophotometric determination of chromium(III) with 4-(2-pyridylazo)-resorcinolAnalytica Chimica Acta, 1973