Diphenylcarbazide Research Articles

Light intensity determines the extent of mercury toxicity in the cyanobacterium Nostoc muscorum

The extent of mercury (Hg) toxicity in the heterocystous cyanobacterium Nostoc muscorum grown for 72 h in three different light intensities was tested for various physiological parameters viz. growth, pigment contents, photosynthesis, respiration, reactive oxygen species (ROS), malondialdehyde formation and antioxidants. A general reduction in growth and pigments, whole cell O2-evolution, photosynthetic electron transport activities and 14CO2-fixation was observed in a metal concentration–dependent manner, and this effect was more pronounced in high light (130 μmol photon m−2 s−1)–exposed cells as compared to low (10 μmol photon m−2 s−1) and normal (70 μmol photon m−2 s−1) light intensity–exposed cells; however, carotenoids and respiration showed reverse trend. Among photosynthetic electron transport activities, whole chain activity was found to be most sensitive in comparison with photosystem II (PS II) and photosystem I (PS I). Comparing the different photosynthetic processes, 14CO2-fixation was most affected in cyanobacterial cells when exposed to Hg and different light intensities. After application of various exogenous electron donors, diphenyl carbazide was found to be more effective to restore PS II activity, suggesting that site of damage lies in between oxygen evolving complex and PS II. Level of oxidative stress (superoxide radical and lipid peroxidation) was maximum at 3.0 μM of Hg when coupled with high light intensity (except hydrogen peroxide). A dose-dependent increase in enzymatic antioxidants such as superoxide dismutase, peroxidase and catalase as well as non-enzymatic antioxidants such as proline, ascorbate, cysteine (except under high light intensity) and non-protein thiols [NP-SH] was observed, which further increased with the increase in light intensity. It was noticed that Hg intoxicates N. muscorum through ROS production, which is aggravated along with the increase in light intensity. Overall results suggest that the severity of the metal stress does increase with Hg concentrations but when coupled with light, it was the light intensity that determines the extent of Hg toxicity.

Spectrophotometric Determination of Ultra trace Tri & Hexavalent Chromium by Using on-line Flow Injection Analysis with Dual Pre-concentration Column

An on-line flow injection analysis with dual pre-concentration method was developed to determine the ultra trace tri and hexavalent chromium in water. In this system, the cation and anion pre-concentration columns were combined with a 10-port injection valve and then used to separate and concentrate Cr (III) and Cr (VI) selectively. The two species of concentrated chromium were sequentially eluted and determined by using HCl-KCl buffer of pH 1.8 as an eluent. Cr (III) was oxidized by hydrogen peroxide to Cr (VI). It was detected spectrophotometrically at 548 nm by complexation with DPC (diphenylcarbazide). Several factors such as concentration of <TEX>$H_2O_2$</TEX>, DPC and coil length in reaction condition were optimized. The linear range for Cr (III) and Cr (VI) was 0.1-50 <TEX>${\mu}g$</TEX>/L. The limit of detections (<TEX>$3{\sigma}$</TEX>) of Cr (III) and Cr (VI) were 52 ng/L and 44 ng/L under the optimized FIA system, and their recoveries 98% and 103%, respectively. This method was applied to analyze contamination level of chromium species in tap water, groundwater and bottled water.

Study on Measurement of Chromium Content in Ramie through UV Spectrophotometry

In this paper, UV spectrophotometry was used to test the chromium content of bast fiber of ramie and diphenylcarbazide (DPC) was used as color reagent. The optimal technology was: dropping volume of phosphoric acid 0.4～0.6 mL, DPC content 2.0~4.0 mL and coloration time 5-10 minutes. The results showed that complexes were formed from Cr (VI) ions and DPC under phosphoric acid condition. There was a maximum positive absorption peak at the 540nm. Cr (VI) concentration (in the range of 0.004～1.000 mgL-1) and the absorbance (A) of complex obeyed the Lambert-Beer law.

Colorimetric determination of copper(II) ions by filtration on sol–gel membrane doped with diphenylcarbazide

A simple and sensitive colorimetric method for the determination of trace copper(II) ions in aqueous solution has been developed using diphenylcarbazide (DPC) immobilized sol–gel matrices. To enhance the odds of chelating interactions between copper(II) ions and DPC, a peristaltic pump was utilized to drive copper(II) ions solution pass through the cellulose acetate/nitrate membrane, which was coated with DPC immobilized sol–gel matrices. The membrane was sandwiched in a home-made flow cell. The porous silica matrix serves as a preconcentrator, and enriches the trace copper(II) ions. Meanwhile, the filtration increases the chelating interaction probability between copper(II) ions and DPC, thereby improves the sensitivity significantly. After the formation of purple complex compound, the color changes of the DPC immobilized sol–gel membrane were recorded using a flatbed scanner. The images were digitized, and the red ( R), green ( G), and blue ( B) values were investigated. The colorimetric method provides a rapid and reliable determination of trace copper(II) ions with a detection limit as low as 0.16 μM and a kinetic range up to 1.6 μM in neutral medium. Moreover, the method shows good selectivity, and the color changes of the DPC immobilized sol–gel membranes are remarkable for the copper(II) ions detection even in the presence of other metal ions.

Interference of Sb(III) in the Determination of Hexavalent Chromium in Thermoplastic Matrices

Due to the adverse health effects of hexavalent chromium, Cr(VI), pigments and other materials containing Cr(VI) were largely banned for use in electrotechnical products under the EU RoHS Directive [1]. While there are several effective methods to determine the presence of total chromium in electrotechnical plastic matrices, a validated compliance test method that is capable of discerning Cr(VI) from the non-regulated forms of Cr(III) is not yet available. One of the challenges in developing a standardized compliance test for Cr(VI) is the low recovery of Cr(VI) compounds from polymer matrices This study identified antimony trioxide (ATO), a common synergist added to enhance the ignition resistance of brominated flame retardants (BFRs), as a source of matrix interference in the quantitative determination of hexavalent chromium extracted from polymer matrices. ATO reduces hexavalent chromium to trivalent chromium prior to complexation of Cr(VI) with diphenylcarbazide (DPC) leading to false negatives. EDTA was found to be an efficient reagent for Sb(III) complexation, thereby suppressing the reduction of Cr(VI) and enabling quantitative Cr(VI) determination in the presence of ATO.

IR spectroscopic analysis of polymorphism in C 13H 14N 4O

IR analysis is used here to investigate the changes in N–N, N–H, C O modes of thermally treated diphenyl carbazide (DPC) during the variation of temperature from room temperature up to ≈160 °C. Polymorphism in DPC compound has been studied here by detecting the changes in some IR spectroscopic parameters (e.g., mode shift, band contour) during the elevation of temperature. Also, DSC, X-ray, NMR and atomic mass spectra are used as confirming tools for what is obtained by IR. All of the vibrations of DPC were found to be due to ionic fundamentals 3311 cm −1, 3097 cm −1, 3052 cm −1, 1677 cm −1, 1602 cm −1, 1492 cm −1, 1306 cm −1, 1252 cm −1, 887 cm −1 and 755 cm −1. The results revealed for the first time that the thermally treated DPC traverse four different phase transformations at 50 °C, 90 °C, 125 °C and 140 °C. The crystal structure was found to be amorphous, monoclinic, tetragonal, orthorhombic and amorphous within a temperature range (30 °C–160 °C). X-ray diffraction patterns support the results obtained by IR and DSC.

A kinetic investigation and X-ray analysis of thermal shrinkage of diphenyl carbazide

The kinetics of thermal shrinkage of diphenyl carbazide (DPC) is investigated above and below room temperature by thermo-mechanical analysis (TMA) at various constant rates of heating. The contraction measurements include two temperature regions. The first lies above 0 °C up to ≈53 °C. The second lies below 0 °C and extended down to −165 °C using liquid nitrogen. Two-stage model is applied here to analyze the TMA data. The activation energy of contraction reaction could be obtained from the TMA curves at different heating rates and found to be 30 Kcal/mol for high temperature thermal shrinkage and 2.7 Kcal/mol for low temperature one. The study reveals the presence of two different characteristic shrinkage anomalies above and below zero temperature for amorphous DPC. This contraction behaviour is attributed to the various kinds of molecular motion of this rigid organic structure. X-ray analysis showed that the shrinkage in amorphous DPC samples ceases behind 50 °C where the amorphous state change to monoclinic crystal structure with a = 15.037 Å, b = 8.242 Å, c = 12.760 Å and α = γ = 90° and β = 99.25° with a space group P21/A. Also, X-ray analysis showed that the low temperature shrinkage is not due to a crystal structure change but can be attributed to a molecular rearrangement process of DPC molecules.

EXTRACTION AND SPECIATION OF CHROMIUM(VI) AND CHROMIUM(III) AS ION-ASSOCIATION COMPLEXES OF TETRAMETHYLAMMONIUM-CHROMATE

A specific, selective and simple method for speciation of chromium(VI) and chromium(III) has been developed. This method is based on the quantitative extraction of chromium(VI) and chromium(III) as an ion association of tetramethylammonium-chromate in methyl isobutyl ketone (MIBK), followed by 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 chromium(VI)-DPC complex was determined by a UV-Visible spectrophotometer. The optimum conditions of this method are as follows, optimum wavelength at 545 nm, MIBK as organic solvent, 7.5 mL of nitric acid (65%) for each 100 mL sample, mole ratio of TMAC to Cr(VI) of 2x104:1, 5 min shaking time, mole ratio of DPC to chromium(VI) of 8:1, and immediate UV-Vis measurement after obtaining of back-extract. The calibration curve was linear in the concentration range 0.00-0.40 µg.mL-1 of chromium(VI) with a regression equation of Abs=0.0038+1.7427x, in which x was the chromium species concentration ( µg.mL-1). The correlation coefficient (r) for the curve was 0.9991 and the detection limit was found to be 0.946 µg.mL-1. The result of analysis and speciation of chromium in water samples from a river near a leather processing plant in Yogyakarta area showed that the total content of chromium was in the range of 0.04 - 0.05 µg.mL-1 consisting of 0.03 - 0.04 µg.mL-1 of chromium(VI) and 0.002 - 0.01 µg.mL-1 of chromium(III). This result indicates that the concentration of chromium in the river is still below the safety limit. Keywords: extraction, speciation, chromium, preconcentration, ion-association, tetramethylammonium

Bioremediation of chromium in tannery effluent by microbial consortia

Chromium is the most toxic and common among the heavy metal pollutants of industrial effluents. In the present work the chromium remediation ability of Bacillus subtilis, Pseudomonas aeruginosa and Saccharomyces cerevisiae in consortia and in their immobilized forms was studied and their efficiencies were compared. Flame Atomic Absorption Spectroscopy and diphenyl carbazide method was used to quantify chromium in the effluent. The chromium content of the effluent was around 770 mg/l before remediation, after which it reduced to 5.2 – 5.7 mg/l. The best activity was observed by S. cerevisiae - P. aeruginosa consortia, followed by immobilized beads of S. cerevisiae and S. cerevisiae - B. subtilis consortia.

Isolation and Characterization of Hexavalent Chromium-Reducing Rhizospheric Bacteria From a Wetland

Scirpus americanus Pers. occurs naturally in “San Germán,” a pond that serves as a receptor of industrial wastewater in Guanajuato, México. This plant accumulates metals mainly in the root: concentrations (mg/kg) of Cr, As, Cd and Se were 970, 49, 41, and 85 respectively. Analysis of rhizosphere samples indicated bacterial population of 108 cfu g−1 in media with 0.2 mM Cr(VI) and 10 mM sodium gluconate. Thirteen isolates were obtained and phylogenetic analyses (16S rRNA) indicated they corresponded to genera of Agrobacterium, Arthrobacter, Microbacterium, Curtobacterium, Rhodococcus, Xanthomonas and Pseudomonas. Cr(VI) reduction was evaluated using the diphenyl carbazide method. The isolates accomplished 5–40% (20 μM) of reduction in assays of resting cell and tolerated 0.5–5.0 mM Cr(VI). Eight strains used nitrate and thirteen used iron and chromium as electron acceptors to grow under anaerobic conditions. Cr(VI) reduction by five strains occurred at pH values (7–9) and NaCl concentrations (0.5–1.0 M) in basal medium. A mixed culture of strains (S17 and S28) reached a chromium removal of 100% at 0.2 mM Cr(VI) initial concentration. Aerobically, this consortium was capable of 93.8% Cr(VI) reduction of 81 μgL−1 Cr(VI) of the industrial effluent, indicating their possible use in environmental cleanup.

Determination of Cr(VI) concentration in diluted samples based on the paper test strip method

At present, there are many methods for Cr(VI) concentration determination in diluted samples, however, these methods have their own inherent drawbacks, such as long response time, complicated pretreatment, expensive equipment etc. In this paper, a paper-based test strip method specific for determination of diluted Cr(VI) samples was developed. In this method, Aliquat 336, as an anion exchanger was loaded into filter paper to form a test strip. This test strip was used to pre-concentrate Cr(VI) when contacting with the diluted Cr(VI)-containing solution. The Cr(VI)-containing test strip was then immersed into a diphenylcarbazide (DPC) solution (a color forming solution), and the color intensity was correlated to the Cr(VI) concentration. The detection range of the present method was found to be 0.02-1.50 mg/L. The results also showed that the method gave a high selectivity for Cr(VI) in the diluted samples to be tested. The method was applied to synthesized samples and the results, which were compared to those from a reference method, showed that the developed method is an effective, reliable way for Cr(VI) determination in diluted samples.

Absence of Chromates in Detergents in India Confirmed by Diphenyl Carbazide Spot Test

Absence of Chromates in Detergents in India Confirmed by Diphenyl Carbazide Spot Test

Investigation of the low-affinity oxidation site for exogenous electron donors in the Mn-depleted photosystem II complexes

In the manganese-depleted photosystem II (PSII[−Mn]) preparations, oxidation of exogenous electron donors is carried out through the high-affinity (HA) and the low-affinity (LA) sites. This paper investigates the LA oxidation site in the PSII(−Mn) preparations where the HA, Mn-binding site was blocked with ferric cations [[11] B.K. Semin, M.L. Ghirardi, M. Seibert, Blocking of electron donation by Mn(II) to YZ• following incubation of Mn-depleted photosystem II membranes with Fe(II) in the light, Biochemistry 41 (2002) 5854–5864.]. In blocked (PSII[−Mn,+Fe]) preparations electron donation by Mn(II) cations to YZ• was not detected at Mn(II) concentration 10 μM (corresponds to Km for Mn(II) oxidation at the HA site), but detected at Mn concentration 100 μM (corresponds to Km for the LA site) by fluorescence measurements. Comparison of pH-dependencies of electron donation by Mn(II) through the HA and the LA sites revealed the similar рKа equal to 6.8. Comparison of Km for diphenylcarbazide (DPC) oxidation at the LA site and Kd for AT thermoluminescence band suppression by DPC in PSII(−Mn,+Fe) samples suggests that there is relationship between the LA site and AT band formation. The role of D1-His190 as an oxidant of exogenous electron donors at the LA site is discussed. In contrast to electrogenic electron transfer from Mn(II) at the HA site to YZ•, photovoltage due to Mn(II) oxidation in iron-blocked PSII(−Mn) core particles was not detected.

Critical Influence of Culture Medium and Cr(III) Quantification Protocols on the Interpretation of Cr(VI) Bioremediation by Environmental Fungal Isolates

The influence of culture medium composition on chromium(VI) quantification according to diphenylcarbazide (DPC) colorimetric determination was evaluated. Considering the eventual biospeciation of Cr(VI) as a mechanism of microbial bioremediation, the possibility to quantify Cr(III) in culture medium was also explored. Yeast nitrogen base (YNB) was identified as the least interferent culture medium for Cr(VI) quantification by DPC and it was applied to compare different strategies for Cr(III) oxidation. The most appropriate oxidation protocol consisted in the reaction with 80 mM KIO4 at room temperature for 30 min prior to DPC. Parameters like basal culture medium (vitamins + salts + oligoelements), C and N source were systematically evaluated, either independently or in combination. Results demonstrated that C source was the most interferent culture medium component, being the use of sucrose preferable to glucose. A medium arbitrarily named as YNB′ (YNB without amino acids and ammonium sulfate plus 50 g L−1 sucrose and 0.6 g L−1 (NH4)2SO4) was defined for Cr(VI)-amended fungal cultures. Kinetics of growth, Cr(VI) removal, and nutrient consumption for isolates A. pullulans VR-8, filamentous fungus PMF-1, and Lecythophora sp. NGV-1 were obtained. The order of Cr(VI) removal efficiency was as follows: A. pullulans VR-8 > Lecythophora sp. NGV-1 > filamentous fungus PMF-1, and a similar trend was observed for biomass yield and nutrients consumption. Studies on biospeciation by means of the selected Cr(III) oxidation protocol were unsuccessful, leading to Cr(VI) values much lower than expected. It revealed that this kind of protocols should be cautiously evaluated when studying microbial Cr(VI) bioremediation.

Physiological response of yellow vein mosaic virus-infected bhendi [ Abelmoschus esculentus] leaves

The effect of okra yellow vein mosaic virus infection on PS II efficiency and thylakoid membrane protein changes in field-grown bhendi ( Abelmoschus esculentus) leaves was studied. The degree of virus infection was determined by means of the ratio of variable to maximum chlorophyll fluorescence ( F v/ F m). Changes in photosynthetic pigments, soluble proteins, nitrate reductase, photosynthetic activities and thylakoid membrane proteins were investigated. Okra yellow vein mosaic virus infection resulted in the reduction of photosynthetic pigments, soluble proteins, ribulose-1, 5-bisphosphate carboxylase activity and nitrate reductase activity. Virus infection caused marked inhibition of PS II activity. The artificial electron donors, diphenyl carbazide and hydroxylamine significantly restored the loss of PS II activity in infected leaves. The marked loss of PS II activity in infected leaves may be due to the loss of 47, 33, 28–25, 17 and 15 kDa polypeptides. It is concluded that the yellow vein mosaic virus infection inactivates the donor side of PS II.

Simultaneous speciation of chromium by spectrophotometry and multicomponent analysis

A simple, fast and sensitive spectrophotometric method for the simultaneous determination of Cr(III) and Cr(VI) in effluents and contaminated waters using a UV-visible spectrophotometer, which operates with an advanced software for multicomponent analysis, is proposed. The method consists in the complexation of Cr (III) with EDTA and reaction of Cr(VI) with diphenylcarbazide (DPC). Variables, such as pH and colour stability time, were studied. The effect of concomitant ions on the simultaneous Cr(III) and Cr(VI) determination was also investigated. The sums of the chromium species concentrations obtained by the proposed method were compared with the total chromium concentrations found by electrothermal atomic absorption spectrometry. Recoveries of the chromium species between 75 and 136% were obtained for spiked samples. The linear working range for Cr(III) was 0.5-30 mg L−1, while for Cr(VI) was 0.005-0.30 mg L−1. The detection limits were 0.3 mg L−1 for Cr(III) and 0.003 mg L−1 for Cr(VI) while the quantification limits were 1.0 mg L−1 for Cr(III) and 0.01 mg L−1 for Cr(VI).

Hybrid mesoporous materials for on-line preconcentration of Cr(VI) followed by one-step scheme for elution and colorimetric determination at ultratrace levels

An hybrid mesoporous material synthesised in our laboratories for solid phase extraction (SPE) in flow through systems has been used for analytical purposes. The solid was obtained from mesoporous silica MCM-41 functionalized with 3-aminopropyltriethoxy silane by Sol–Gel methodology. In order to exploit the large sorption capacity of the material together with the possibility of modeling it for anions retention, a microcolumn (MC) filled with the solid was inserted in a flow system for preconcentration of Cr(VI) and its determination at ultratrace levels in natural waters. The analytical methodology involved a reverse flow injection system (rFI) holding a MC filled with the solid for the analyte extraction. Elution and colorimetric detection were carried out with 1–5 diphenylcarbazide (DPC) in sulfuric acid. DPC produced the reduction of Cr(VI) to Cr(III) together with the generation of a cationic red complex between Cr(III) and 1–5 diphenylcarbazone which was easily eluted and detected with a visible spectrophotometer. Moreover, the filling material got ready for the next sample loading remaining unspoiled for more than 300 cycles. The effect of several variables on the analytical signal as well as the influence of cationic and anionic interferences were discussed. Particular attention was given to sulfuric acid interference since it is the required media for the complex generation. Under optimal conditions, 99.8% of Cr(VI) recovery was obtained for a preconcentration time of 120 s (sample and DPC flow rates = 1 mL min −1) and an elution volume of 250 μL. The limit of detection (3 s) was found to be 0.09 μg L −1 Cr(VI) with a relative standard deviation ( n = 10, 3 μg L −1) of 1.8. Since no Cr(III) was retained by the solid material and Cr(VI) was completely adsorbed, electrothermal atomic absorption spectrometry (ET AAS) determinations of Cr(III) were also performed by simply measuring its concentration at the end of the microcolumn after Cr(VI) retention by the mesoporous solid. Applications to the determination of Cr(VI) and Cr(III) in natural waters and the validation of the methodology were also studied.

Inhibition and Uncoupling of Photosynthetic Electron Transport by Diterpene Lactone Amide Derivatives

Nine diterpene lactone amide derivatives 1-9 were synthesized from 6-oxovouacapan-7beta,17beta-lactone, which was obtained from 6alpha,7beta-dihydroxyvouacapan-17beta-oic acid isolated from Pterodon polygalaeflorus Benth., and tested for their activity on photosynthetic electron transport. Amide derivatives 3-5 behaved as electron transport chain inhibitors; they inhibited the photophosphorylation and uncoupled non-cyclic electron transport from water to methylviologen (MV). Furthermore, 4 and 5 enhanced the basal electron rate acting as uncouplers. Compound 6 behaved as an uncoupler; it enhanced the light-activated Mg2+-ATPase and basal electron flow, without affecting the uncoupled non-cyclic electron transport. Compounds 1-2 and 7-9 were less active or inactive. Compounds 3-5 did not affect photosystem I (PSI); they inhibited photosystem II (PSII) from water to 2,6-dichlorophenol indophenol (DCPIP). Compound 4 inhibited PSII from water to silicomolybdate (SiMo), but it had no effect on the reaction from diphenylcarbazide (DPC) to DCPIP indicating that its inhibition site was at the water splitting enzyme complex (OEC). Compounds 3 and 5 inhibited PSII from water to DCPIP without any effect from water to SiMo, therefore they inhibited the acceptor site of PSII. Chlorophyll a fluorescence kinetics confirmed the behaviour of 3-5.

IMPACT OF BLEACHING STRESS ON THE FUNCTION OF THE OXYGEN EVOLVING COMPLEX OF ZOOXANTHELLAE FROM SCLERACTINIAN CORALS(1).

Global climate change is leading to the rise of ocean temperatures and is triggering mass coral bleaching events on reefs around the world. The expulsion of the symbiotic dinoflagellate algae is believed to occur as a result of damage to the photosynthetic apparatus of these symbionts, although the specific site of initial impact is yet to be conclusively resolved. Here, the sensitivity of the oxygen evolving complex (OEC) to bleaching stress was studied as well as its natural variation between seasons. The artificial electron donor, diphenyl carbazide (DPC), was added to cultured, freshly isolated and expelled (bleaching treatments only) zooxanthellae suspensions. Chl a fluorescence and oxygen production measurements showed that upon addition of DPC, no restoration of diminished photochemical efficiency occurred under control or bleaching conditions. This result was consistent between 12 h and 5 d bleaching treatments on Pocilloporadamicornis, indicating that the OEC is not the primary site of damage, and that zooxanthellae expulsion from the host is a nonselective process with respect to the functioning of the OEC. Further experiments measuring fast induction curves (FICs) revealed that in both summer and winter, the temperature when OEC function was lost occurred between 7°C and 14°C above the sea surface temperature. FIC and oxygen production measurements of P. damicornis during exposure to bleaching stress demonstrated that the thermotolerance of the OEC increased above the temperature of the bleaching treatment over a 4 h period. This finding indicates that the OEC has the capacity to acclimate between seasons and remains functional at temperatures well above bleaching thresholds.

Solid phase extraction of chromium (VI) from aqueous solutions by adsorption of its diphenylcarbazide complex on an alumina column

Abstract A simple method has been developed for the solid phase extraction of chromium (VI) based on the adsorption of its diphenylcarbazide (DPC) complex on an alumina column. The effect of various parameters such as acidity, stability of the column, sample volume, and interfering ions have been studied in detail. The adsorbed complex could be easily desorbed using sulphuric acid and the concentration of chromium has been established using atomic absorption spectrophotometry and visible spectrophotometry. The calibration graph was linear in the range of 0–1 µg/mL chromium (VI) with a detection limit of 4 µg/L. A highest preconcentration factor of 125 could be obtained for 5000 mL sample volume using glass wool as support for alumina. Chromium (VI) could be effectively separated from other ions such as zinc, nickel, copper, chloride, sulphate, and nitrate and the method has been successfully applied to study the recovery of chromium in spiked well water and tap water samples.