Copper In Environmental Samples Research Articles

Preparation of a magnetic polystyrene nanocomposite for dispersive solid-phase extraction of copper ions in environmental samples

The core shell nanostructure of magnetic polystyrene (PS@Fe3O4) was prepared and its physic-chemical properties were studied FT-IR, SEM, TEM, VSM and BET + BJH. The new adsorbent was applied in the dispersive solid phase extraction technique for measuring copper ions in water, Soil and Oyster samples. Analysis is carried out using a flame atomic absorption spectrometry system. Effective parameters on extraction efficiency, such as pH of extraction solution, sorbent dosage, contact time, concentration and volume of desorption eluent and desorption time were optimized using one at a time method. N2 adsorption-desorption experiment resulted in high BET surface area (32.002 m2 g−1) and large pore volume (0.1794 cm3 g−1) for PS@ Fe3O4 nanocomposite. Under the optimum conditions, a calibration curve within the range of 5–40 ng mL−1 with an appropriate coefficient of determination (R2) of 0.9946 was obtained. Preconcentration factor (PF) and limit of detection (LOD) were found to be 55 and 1.6 ng mL−1, respectively. The repeatability and reproducibility for three replicate measurements at the concentration of 25 ng mL−1 were 2.5%–1.4%, respectively. The Freundlich adsorption isotherm and pseudo-second-order kinetic model were consistent to experimental data in adsorption mechanism study. The maximum adsorption capacity was 19.56 mg g−1 for Cu (II). Finally, the efficiency of the method was investigated for analysis of the copper in environmental samples and good relative recoveries (RR%) were obtained within the range of 99.2% to 101.2%.

An efficient green microextraction method of Co and Cu in environmental samples prior to their flame atomic absorption spectrometric detection

ABSTRACT A dispersive liquid-liquid microextraction procedure (DLLME) was developed and validated for the determination of cobalt and copper in environmental samples by flame atomic absorption spectrometry. The optimisation parameters of DLLME procedure including amount of chelating reagent (0.05 mg dithizone), pH (6), extraction type and volume (250 µL chloroform) and dispersive solvent (1000 µL acetone), matrix effect was investigated. Several validation variables, such as limit of detection and quantification, linearity, recovery, precision and trueness were also tested. The quantification limits of Co and Cu were found to be 9.01 and 6.14 µg L−1, respectively. The enrichment factor was 20. The trueness of the method was tested by analysis of certificated reference material (BCR-715) for Cu and calculated less than −1.11% with the relative error. The presented green microextraction method was profitably applied to real samples and the spiked recoveries calculated were more than 95% with the relative standard deviation less than 8.4%.

Assessing the contributions of metals in environmental media to exposure biomarkers in a region of ferroalloy industry.

Residential proximity to ferroalloy production has been associated with increased manganese exposure, which can adversely affect health, particularly among children. Little is known, however, about which environmental samples contribute most to internal levels of manganese and other ferroalloy metals. We aimed to characterize sources of exposure to metals and evaluate the ability of internal biomarkers to reflect exposures from environmental media. In 717 Italian adolescents residing near ferromanganese industry, we examined associations between manganese, lead, chromium, and copper in environmental samples (airborne particles, surface soil, indoor/outdoor house dust) and biological samples (blood, hair, nails, saliva, urine). In multivariable regression analyses adjusted for child age and sex, a 10% increase in soil Mn was associated with increases of 3.0% (95% CI: 1.1%, 4.9%) in nail Mn and 1.6% (95% CI: −0.2%, 3.4%) in saliva Mn. Weighted-quantile-sum (WQS) regression estimated that higher soil and outdoor dust Mn accounted for most of the effect on nail Mn (WQS weights: 0.61 and 0.22, respectively, out of a total of 1.0). Higher air and soil Mn accounted for most of the effect on saliva Mn (WQS weights: 0.65 and 0.29, respectively). These findings can help inform biomarker selection in future epidemiologic studies and guide intervention strategies in exposed populations.

Haemostatic Agent as New Ionophore for Selective Determination of Copper in Environmental Samples and Pharmaceutical Formulations.

The construction and electrochemical response characteristics of poly vinyl chloride (PVC) membrane sensors for the determination of copper were described. The sensors are based on using of ethamsylate as an ionophore and dioctylphethalate (DOP) as a plasticizer in the PVC matrix. Conventional and graphite membrane sensors were prepared and the performance characteristics are evaluated according to IUPAC recommendations, reveal fast, stable and linear response for copper over the concentration range 1×10−6-1×10−2 M and 7×10-5 -1×10-2 M with cationic slopes of 29.5 and 27.8 mV per concentration decade at pH 5 for conventional and graphite membrane sensors respectively. The potentiometric selectivity data revealed no interference from common cations. The direct potentiometric determination of copper using the proposed sensors gave average recoveries of 99.89 ± 0.9 and 100.04 ± 1.1 for the conventional and graphite sensors, respectively. The sensors are used for direct measurement of copper content in industrial waste water, metal alloys samples from copper factories and pharmaceutical formulations. The developed method was found to be simple, accurate and precise when compared with a reported atomic absorption method.

Microwave supported spectrophotometric determination of copper in environmental samples

Microwave supported spectrophotometric determination of copper in environmental samples

Sensitive determination of copper in water samples using dispersive liquid-liquid microextraction-slotted quartz tube-flame atomic absorption spectrometry

Determination of trace amount of copper in environmental samples is necessary due to its toxic properties and dangers to living organisms. Dispersive liquid-liquid microextraction (DLLME) was coupled with slotted quartz tube (SQT) to lower the detection limit for copper using flame atomic absorption spectrometry (FAAS). Parameters affecting the formation of copper-ligand complex, DLLME efficiency and SQT output were systematically optimized to improve copper detection signal. The SQT-FAAS, DLLME-FAAS and DLLME-SQT-FAAS systems were 2, 42 and 79 times, respectively, more sensitive than the conventional FAAS system. The limit of detection (LOD) and quantitation (LOQ) values obtained for the combined methods (DLLME-SQT-FAAS) were calculated as 0.7 and 2.2μgL−1, respectively. The method recorded appreciable recoveries for all samples tested (78%–99%), and experimental results of a certificated references material (EU-L-2) agreed with the certified value.

Voltammetric determination of copper in water samples using a Schiff base/carbon nanotube-modified carbon paste electrode

In the present study, a novel Schiff base modified multiwalled carbon nanotube paste sensor was developed for the determination of trace amounts of copper in environmental samples. It is based on the encapsulation of the C24H30N6 Schiff base onto multiwalled carbon nanotube paste electrode. The operating conditions regarding supporting electrolytes, deposition time and applied potential on the sensitivity of electrode were established and optimized in detail. The working curve was linear in the concentration range of 0.09–340μgL−1. The relative standard deviation for 3 replicate determination of the 30μgL−1 Cu(II) was 1.47%. The detection limit and quantification limit were 0.01 and 0.06μgL−1, respectively. The sensor was successfully applied to the determination of copper in the river and city water.

Development a novel supramolecular solvent microextraction procedure for copper in environmental samples and its determination by microsampling flame atomic absorption spectrometry

A supramolecular solvent (Ss) made up of reverse micelles of 1-decanol in tetrahydrofuran (THF): water was used for the fast and selective microextraction of Cu(II) prior to its determination by microsampling flame atomic absorption spectrometry (FAAS). Cu(II) was complexed with dimethyl dithiocarbamate (DMDC) to obtain hydrophobic complex and extracted to supramolecular solvent phase. The influences of some analytical parameters including pH, type and volume of supramolecular solvent, amount of complexing agent, ultrasonication and centrifuge time and sample volume were investigated. The effects of matrix components were also examined. The detection limit (LOD) and the quantification limit (LOQ) were 0.52µgL−1 and 1.71µgL−1 respectively. An preconcentration factor was obtained as 60 and the relative standard deviation was <3%. The accuracy of the developed method was evaluated by the analysis of the certified reference materials (TMDA-64.2 water, SRM 1568A Rice Flour and 8433 Corn Bran) and addition-recovery tests. The presented supramolecular solvent based liquid–liquid microextraction (SsLLME) procedure was applied to the determination of copper in food and water samples with satisfactory results.

Determination of Trace Copper in Environmental Samples by Flame Atomic Absorption Spectrometry After On-line Selective Preconcentration with Thioacetamide Modified Silica Gel Mini-Column

Determination of Trace Copper in Environmental Samples by Flame Atomic Absorption Spectrometry After On-line Selective Preconcentration with Thioacetamide Modified Silica Gel Mini-Column

Separation and preconcentration of copper in environmental samples on Amberlite XAD-8 resin after complexation with a carbothioamide derivative

A new solid phase extraction (SPE) method has been developed for the selective separation and preconcentration of Cu (II) ions in food and water samples prior to its flame atomic absorption spectrometry determination. The method is based on the adsorption of the Cu(II) - 2-{[4-Amino-3-(4-methylphenyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl]acetyl}-N-phenyl hydrazinecarbothioamide complex on Amberlite XAD-8 resin. The metal complex retained on the resin was eluted with 7.5 mL of 2.0 mol L-1 HCl in acetone. The optimum conditions for the SPE of Cu(II) ions were investigated, and the method was subsequently applied to sea water, stream water, rice, tea, and tobacco samples for the determination of Cu(II) levels.

Diethyldithiocarbamate functionalized CdSe/CdS quantum dots as a fluorescent probe for copper ion detection

A new fluorescent probe for copper ion detection is reported that it is based on the quenching of the fluorescence of the diethyldithiocarbamate (DDTC)-functionalized quantum dots (QDs) in the presence of copper ions. DDTC was bound to the QDs via the surface ligand exchange to form DDTC–QDs conjugates following the capping of 2-mercaptoacetic acid on the core–shell CdSe/CdS QDs. It was found that the fluorescence intensity of the conjugates was quenched after coordinated with Cu 2+. A linear relationship existed between the extent of quenching and the concentration of copper in the range of 0–100 μg L −1, with a detection limit of 0.29 μg L −1 (3 σ). The DDTC-functionalized QDs showed excellent selectivity for Cu 2+ over other metal cations. The fluorescent probe was successfully used for the determination of copper in environmental samples.

Effect of copper on the activation of the acid phosphatase from the green algae Pseudokirchneriella subcapitata

The presence of copper in water environment may have detrimental effects on aquatic organisms, including algae, where different enzymatic systems can be affected. Algae acid phosphatase plays important roles in metabolic processes such as decomposition of organic phosphate, autophagic digestive process, recycling cellular materials and zygote formation during reproduction. This work describes an in vitro activation effect of copper on the acid phosphatase of the green algae Pseudokirchneriella subcapitata (formely Selenastrum capricornutum) under preincubation condition. Apparent Michaelis constant values of 1.21 and 0.37 mM, and activation energy values of 26.8 and 13.6 kJ mol(-1) were determined in the absence and in the presence of 0.2 mM Cu(2+), respectively. The dissociation constant value for Cu(2+) binding to the enzyme was determined to be 22.04 microM. The decrease of the apparent Michaelis constant (Km) and activation energy values in the presence of Cu(2+) correlates well with its activating effect on the acid phosphatase activity. This propriety could be used as a sensitive bioindicator for copper in environmental samples.

Selective separation and preconcentration of copper (II) in environmental samples by the solid phase extraction on multi-walled carbon nanotubes

A solid phase extraction method for selective separation–preconcentration of copper (II) on multi-walled carbon nanotubes (MWNTs) prior to its flame atomic absorption spectrometric determinations has been investigated. The adsorption was achieved quantitatively on MWNTs column at pH 7.0, then the retained Cu(II) contents on the column were quantitatively eluted with 2 M HNO 3. The effects of analytical parameters including pH of the solution, eluent type, sample volume, flow rates of eluent, matrix ions etc. were investigated for optimization of the presented procedure. The preconcentration factor was 60. The detection limit for copper (II) was found as 1.46 μg/L. The method was applied to the determination of copper in environmental samples and reproducible results were obtained.

Application of cotton as a solid phase extraction sorbent for on-line preconcentration of copper in water samples prior to inductively coupled plasma optical emission spectrometry determination

Copper, as a heavy metal, is toxic for many biological systems. Thus, the determination of trace amounts of copper in environmental samples is of great importance. In the present work, a new method was developed for the determination of trace amounts of copper in water samples. The method is based on the formation of ternary Cu(II)–CAS–CTAB ion-pair and adsorption of it into a mini-column packed with cotton prior applying inductively coupled plasma optical emission spectrometry (ICP-OES). The experimental parameters that affected the extraction efficiency of the method such as pH, flow rate and volume of the sample solution, concentration of chromazurol S (CAS) and cethyltrimethylammonium bromide (CTAB) as well as type and concentration of eluent were investigated and optimized. The ion-pair (Cu(II)–CAS–CTAB) was quantitatively retained on the cotton under the optimum conditions, then eluted completely using a solution of 25% (v/v) 1-propanol in 0.5 mol L −1 HNO 3 and directly introduced into the nebulizer of the ICP-OES. The detection limit (DL) of the method for copper was 40 ng L −1 ( V sample = 100 mL) and the relative standard deviation (R.S.D.) for the determination of copper at 10 μg L −1 level was found to be 1.3%. The method was successfully applied to determine the trace amounts of copper in tap water, deep well water, seawater and two different mineral waters, and suitable recoveries were obtained (92–106%).

Cloud point extraction for the determination of copper in environmental samples by flame atomic absorption spectrometry

A simple cloud point extraction procedure is presented for the preconcentration of copper in various samples. After complexation by 4-hydroxy-2-mercapto-6-propylpyrimidine (PTU), copper ions are quantitatively extracted into the phase rich in Triton X-114 after centrifugation. Methanol acidified with 0.5 mol L -1 HNO 3 was added to the surfactant-rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS). Analytical parameters including concentrations for PTU, Triton X-114 and HNO 3 , bath temperature, centrifugation rate and time were optimized. The influences of the matrix ions on the recoveries of copper ions were investigated. The detection limits (3SD b /m, n=4) of 1.6 ng mL -1 along with enrichment factors of 30 for Cu were achieved. The proposed procedure was applied to the analysis of environmental samples.

&lt;b&gt;Microwave assisted spectrophotometric method for the determination of copper using leucocrystal violet&lt;/b&gt;

A sensitive spectrophotometric method has been developed for the trace determination of copper using leucocrystal violet as chromogenic reagent. The proposed method is based on the reaction of copper(II) with potassium iodide in acid medium to liberate iodine, which oxidizes leucocrystal violet to crystal violet dye having absorption maximum at 590 nm. The reaction between copper and potassium iodide is accelerated by irradiating the mixture with microwave energy for 15 s at 480 W. Beer’s law is obeyed in the concentration range 0.004 – 0.04 µg mL -1 . The molar absorptivity, Sandell’s sensitivity, detection limit and quantitation limit were found to be 1.47 x 10 6 L mol -1 cm -1 , 4.3 x 10 -5 µg mL -2 , 0.001 µg mL -1 , 0.0043 µg mL -1 , respectively. The optimum conditions and other analytical parameters were evaluated. The effect of interfering ions on the determination is described. The proposed method has been successfully applied for the determination of copper in environmental samples like tap water, agricultural run off water, plant materials and pharmaceutical samples. KEY WORDS: Spectrophotometry, Copper determination, Leucocrystal violet Bull. Chem. Soc. Ethiop. 2007 , 21(1), 129-134.

Nanostructuring of Langmuir‐Blodgett Films Containing a Novel Thiomacrocyclic Ionophore on Si3N4/SiO2/Si for Copper Ion Recognition

In its ionic form, copper is a potentially toxic substance, thus, there is a need for developing a sensor to detect low levels of copper in environmental samples. A new capacitive biosensor sensitive to copper(II) was developed. This was achieved by the deposition of the new synthesized ionophore 4‐phenyl‐4‐sulfide‐11‐(1‐oxodecyl)‐1,7‐dithia‐11‐aza‐4‐phosphacyclotetradecane using the Langmuir‐Blodgett (LB) technique. The LB films formed on the Si3N4/SiO2/Si substrate were characterized using X‐ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and electrochemical impedance spectroscopy (EIS). The shift of the admittance curves owing to the variation of the Cu2+ concentration shows that the device is sensitive to this ion.

A novel voltammetric method for the direct determination of copper in complex environmental samples.

A novel voltammetry with a modified gold electrode for the direct determination of copper in environmental samples, without any pretreatment, is proposed in this paper. A porous disorganized monolayer was formed on the surface of the gold electrode by the self-assembly of mercaptoacetic acid (MAA), which could selectively permeate small molecules. Subtractive square wave anodic stripping voltammetry (SASV) was applied to determine copper, in which the underpotential deposition (UPD) of copper was used as the deposition step. The linear range was from 8 x 10(-7) to 1 x l0(-5) mol l(-1) by the modified electrode in the presence of human serum albumin, and the determination was not interfered with common metal ions. Copper in a real environmental sample was successfully detected.

ChemInform Abstract: Development of Trace Metal Ion Analysis

Analyses of trace biologically essential or toxic ionic compounds found in the environment are very important. However, the lack of sensitivity and interference caused by coexisting components are often serious problems. To determine trace levels of metal ions without the above problems, new preconcentration and analytical methods have been developed. Firstly, three methods for the selective preconcentration of metal ions are shown below: 1) 3-Chloropyridazine-6-carbohydrazide was immobilized on glass beads supports to be used as a column packing material. Multi-metal ions were concentrated on the column and eluted selectively with several buffers and hydrochloric acid. The eluate was analyzed off-line by flame atomized-atomic absorption spectrometry (AAS). This method was able to determine sub-ppb levels of cupper- and cadmium-ions in environmental samples. 2) Salicylideneamino-2-thiophenol was immobilized on the supports. Aluminum ion was concentrated selectively on the column and eluted with nitric acid. The eluate was analyzed off-line by flameless-AAS or on-line by flow injection analysis using pyrocatechol violet for a post-column colorimetric reagent. These methods were able to determine ppb-ppt levels of aluminium in environmental samples and were suitable for its state-analysis. 3) Bathocuproinesulfonic acid was immobilized on the supports. Copper ion was concentrated selectively on the column and eluted with nitric acid. The eluate was analyzed on-line by flow injection analysis using bathocuproinesulfonic acid. This method was able to determine sub-ppb levels of copper in environmental samples. On the other hand, to analyze simultaneously trace metal ions and anions, capillary electrophoresis was performed using ethylenediaminetetraacetic acid as an electrolyte component. Simultaneous determination of several ions in mineral waters was achieved by the system.

A new spectrophotometric reagent for copper: 3,3′-(1,3-propanediyldiimine)bis-[3-methyl-2-butanone]dioxime

A new reagent 3,3′-(1,3-propanedyldiimine)bis-[3-methyl-2-butanone]dioxime (PnAO) has been prepared and used for developing a simple spectrophotometric method for the determination of copper which is based on a 1 : 1 complex formation between copper(II) and PnAO in aqueous solution. The method is optimized in terms of pH, stability of the complex, amount of reagent required, sensitivity, linearity and tolerance limits of various foreign ions. The new photometric method was also applied for the determination of copper in environmental samples.