Simultaneous Determination Of Cu Research Articles

Direct Cu, Fe, and Ni Ions Multicomponent Analysis Using UV-Vis Spectrophotometric Method

This study presents a direct multicomponent analysis method using UV-Vis spectrophotometry to determine Cu(II), Fe(III), and Ni(II) ion content without prior complexation or separation. Single and multivariate regression was used to predict metal ion content, and the resulting model was trained and validated using a dataset of 25 multi-component samples. The mean recoveries for Cu(II), Fe(III), and Ni(II) using linear and ridge regression based only on absorbance at 805 nm were 99.97% and 101.6%, 95.42% and 95.65%, and 99.43% and 99.99%, respectively, for the 20% test data. The mean recoveries for Cu(II), Fe(III), and Ni(II) using linear and ridge regression based only on absorbance at 805 nm were 92.27% and 95.03%, 125.3% and 124.11%, and 104.15% and 105.52%, respectively, for the test solution outside of the training data. These results demonstrate the effectiveness of the multivariate UV-Vis spectrophotometric method for the simultaneous determination of Cu(II) and Ni(II) in multicomponent samples, which meets the analysis standard and can be successfully applied. Finally, the study sheds light on the influence of spectral interference on the accuracy of regression models. It highlights the importance of carefully selecting the wavelengths used as predictors in such models. This can have significant implications for developing and validating analytical methods, particularly in cases where multiple analytes were present in a sample.

Using a biphasic system and digital imaging analysis with chemometric tools for simultaneous determination of Cu2+ and furfural in cachaça.

The present study reports, for the first time, the development and application of a highly efficient method based on digital imaging analysis for the simultaneous determination of Cu2+ and furfural in cachaça samples using a two-phase system and chemometrics tools. Furfural reacts with aniline in an acidic medium to form a Schiff base, which exhibits a pink color. On the other hand, Cu2+ reacts with cuprizone in a basic medium to form a blue complex. The two reactions were performed on a porcelain plate, and a smartphone was used to capture the colorimetric images. Partial least squares (PLS) regression was used to construct the prediction models for Cu2+ and furfural contents in cachaça samples. After finding the best PLS models, the ordered predictor selection (OPS) analysis was performed in order to select the most predictive variables. The method developed was found to be effective in estimating the amounts of Cu2+ and furfural in cachaça samples, with a mean absolute error of 0.2 mg L-1 for the Cu2+ model, and 0.3 mg per 100 mL of anhydrous alcohol for the furfural model. The method proposed in this study is simple and straightforward; it does not require complex technical knowledge and can be used by the producers themselves in the cachaça manufacturing process.

On-Line Preconcentration and Simultaneous Determination of Cu and Mn in Water Samples Using a Minicolumn Packed with Sisal Fiber by MIP OES.

An on-line preconcentration system for the simultaneous determination of Copper (Cu) and manganese (Mn) in water samples was developed and coupled to a microwave-induced plasma optical emission spectrometer (MIP OES). The flow injection system was designed with a minicolumn packed with sisal fiber (Agave sisalana). A multivariate experimental design was performed to evaluate the influence of pH, preconcentration time, and eluent concentration. Optimal conditions for sample preparation were pH 5.5, preconcentration time was 90 s, and HCl 0.5 mol L−1 was the eluent. The main figures of merit were detection limits 3.7 and 9.0 µg L−1 for Cu and Mn, respectively. Precision was expressed as a relative standard deviation better than 10%. Accuracy was evaluated via spiked recovery assays with recoveries between 75–125%. The enrichment factor was 30 for both analytes. These results were adequate for water samples analysis for monitoring purposes. The preconcentration system was coupled and synchronized with the MIP OES nebulizer to allow simultaneous determination of Cu and Mn as a novel sample introduction strategy. The sampling rate was 20 samples/h. Sisal fiber resulted an economical biosorbent for trace element preconcentration without extra derivatization steps and with an awfully time of use without replacement complying with the principles of green analytical methods.

Magnetic nanobiosorbent (MG-Chi/Fe3 O4 ) for dispersive solid-phase extraction of Cu(II), Pb(II), and Cd(II) followed by flame atomic absorption spectrometry determination.

Trace amounts of Cu (II), Pb (II), and Cd (II) in a wastewater sample were preconcentrated with a novel cross‐linked magnetic chitosan modified with a new synthesised methionine‐glutaraldehyde Schiff's base (MG‐Chi/Fe3O4) as a dispersive solid‐phase extraction (DSPE) adsorbent. The adsorbed metal ions were then eluted with a specific volume of suitable solution and determined by flame atomic absorption spectrometry (FAAS). Various parameters affecting the extraction efficiency of the metal ions were investigated and optimised, including pH, amount of adsorbent, extraction time, type and volume rate of eluent, elution time, sample volume, and effect of interfering ions. The adsorption kinetics are more consistent with the pseudo‐second order model. The results were statistically interpreted and the analytical performance of the proposed method was found to have preconcentration factors of 55, 60, and 50 μg L−1 for Cu(II), Pb(II), and Cd(II), respectively, limits of detection were 0.22, 0.24, and 0.10 μg L−1 for Cu(II), Pb(II), and Cd(II), respectively, with a relative standard deviation (1.5%‐2.8 %), and the liner range was 5–1000 for Cu(II) and Pb(II) and 2.5–1000 for Cd(II). It was concluded that this method was suitable for successful simultaneous determination of Cu(II), Pb(II), and Cd(II) in industrial wastewater samples.

A polymer inclusion membrane for the simultaneous determination of Cu(II), Ni(II) and Cd(II) ions from natural waters

A novel polymer inclusion membrane (PIM), doped with pyridine-2-acetaldehyde benzoylhydrazone (2-APBH) as extractant, was synthesized and applied for the simultaneous extraction and preconcentration of Cu(II), Ni(II) and Cd(II) ions from natural waters of different salinities. Poly(vinyl chloride) (PVC) and tributyl phosphate (TBP) were used to prepare the polymeric membrane. The carrier-mediated extraction of Cu(II), Ni(II) and Cd(II) ions by PIM was based on the reaction of 2-APBH as a polydentate ligand, forming uncharged chelates at pH 8. After a back-extraction step from the membrane to an acid solution (0.3 mol L-1 nitric acid), these ions were quantitative determined by flame atomic absorption spectroscopy. The optimum values of different analytical variables were determined by using the modified simplex method. The results showed limits of detection of 0.33 µg L-1 for Cu(II), 0.75 µg L-1 for Ni(II) and 0.48 µg L-1 for Cd(II). The accuracy was successfully assessed by analyzing a certified reference river water (LGC 6019). The applicability of the proposed PIM on real samples was also demonstrated on estuarine and seawater samples, with high salinities.

Rapid and simultaneous electrochemical method to measure copper and lead in canine liver biopsy

The conventional analytical techniques used for the quantitative analysis of heavy metals in animal tissues are the atomic absorption spectroscopy (AAS) and the inductively-coupled plasma mass spectrometry (ICP-MS). These methods involve high cost, skilled personnel and long analysis times. Several studies have shown the applicability of electrochemical transducer coupled to disposable screen-printed electrodes (SPE) for measuring metals. The aim of the present study was to applicate and validate a simple and fast protocol for the simultaneous measurement of Cu and Pb concentrations in canine liver biopsy, coupling a simple digestion procedure with electrochemical stripping analysis. Square wave anodic stripping voltammetry (SWASV) coupled to disposable SPE was employed as fast and sensitive method for metals detection. Samples were digested with hydrogen peroxide/hydrochloric acid mixture for 1 h coupled to solid phase purification with carbon columns. Instrumental precision, digestion procedure accuracy and limits of detections were evaluated. To validate the proposed method the metal concentrations have also been determined by AAS. Instrumental precision and digestion method accuracy were less than 15.3% and 16.8% for Cu and Pb, respectively. The limits of detection were 10 and 6 mg/kg dry weight in liver samples for Cu and Pb, respectively. The results obtained by the electrochemical method are in agreement with those of the reference method. The obtained results showed a reliable approach for Cu and Pb detection simultaneously with good sensitivity, accuracy and precision. The simple sample pre-treatment together with the low cost makes this approach particularly appealing for Cu and Pb quantification for diagnostic purposes.•Simultaneous determination of Cu and Pb concentrations in canine liver biopsy.•Square wave anodic stripping voltammetry (SWASV) with screen-printed electrodes (SPE) coupled to an acid digestion protocol.•Cu and Pb were measured with a very good sensitivity and accuracy.•Good agreement with AAS reference method.•Low cost, fast and sensitive method for diagnostic purposes.

Fabrication and Application of a New Modified Electrochemical Sensor Using Newly Synthesized Calixarene-Grafted Mwcnts for Simultaneous Determination of Cu(II) and Pb(II)

A rapid, simple, selective and highly sensitive simultaneous determination of Cu(II) and Pb(II) via newly fashioned 5,11,17,23-tetra-tert-butyl-25,27-dihydrazinamidecarbonylmethoxy-26,28-dihydroxycalix[4]arene-grafted multi-walled carbon nanotubes-modified carbon paste electrode (CNT-Calix/CPE) by differential pulse anodic stripping voltammetry (DPASV) has been introduced. It was observed that CNT-Calix/CPE exhibits higher selectivity and stability for Cu(II) and Pb(II). Different operational parameters such as pH, deposition potential/time, pulse amplitude (5, -1.0 V vs. Ag/AgCl, 300 s, 2 s, 0.05 V) were also optimized for calculation and statistical evaluation of linear range, detection limit and limit of quantification. Interference study shows that the electrode is highly selective for the simultaneous determination of Cu(II) and Pb(II). Standard addition method was used to apply CNT-Calix/CPE in waste water, plant leaves and soft drinks and it was found that the concentration of Cu(II) and Pb(II) were corresponding to standardized values.

N-Doped carbon dots with pH-sensitive emission, and their application to simultaneous fluorometric determination of iron(III) and copper(II).

Simultaneous fluorometric determination of iron(III) and copper(II) without the use of any masking agent or additional treatment is achieved by using N-doped carbon dots (NCDs). The NCDs were hydrothermally prepared, have strongest excitation/emission peaks at 320/406nm and a 47% quantum yield. Excitation-tunable emission is found to depend on solution pH values. This supports the involvement of surface states in the origin of the excitation dependent nature. The NCDs were employed as a fluorescent probe for the simultaneous determination of Fe(III) with a linear response in the 3-60μM concentration range and a 0.31μM detection limit (LOD). The probe also responds linearly to Cu(II) in the 0.5-15μM concentration range and witha 56nM LOD. With the addition of Cu(II), the absorption spectra of NCDs presented a clear decrease in the intensity at 312nm followed by an increase at 360nm. This is not observed in the presence of Fe(III). The fluorescence lifetime of NCDs (5.8ns) is reduced by Fe(III) but not by Cu(II). Thus, the two metal ions can be simultaneously detected without the need for any reagents. The probe was employed to quantify Fe(III) and Cu(II) in spiked water, serum, and urine samples. Graphical abstract Schematic representation of hydrothermal synthesis of highly fluorescent N-doped carbon dots with novel pH dependent emission and their application for the simultaneous determination of Cu(II) and Fe(III) with individual ion discrimination.

A Novel Electrochemical Sensor Based on A Glassy Carbon Electrode Modified with GO/MnO2 for Simultaneous Determination of Trace Cu(II) and Pb(II) in Environmental Water

AbstractIn this study, manganese dioxide hybridized with graphene oxide (GO/MnO2) nanocomposite was prepared by a facile synthesis method, which was applied to modify the glassy carbon electrode (GCE) in an electrochemical sensor of Cu(II) and Pb(II) for the first time. The morphology and structure of the nanocomposite were investigated by scanning electron microscopy, transmission electron microscopy and X‐ray diffraction, which exhibited MnO2 had been uniformly attached to the lamellar structure of GO, resulting in more adsorptive sites. Electrochemical properties of GO/MnO2/GCE were characterized by cyclic voltammetry and electrochemical impedance spectroscopy and the result confirmed GO/MnO2/GCE had an excellent electrochemical performance. Furthermore, the important factors affecting on the sensor sensitivity, including pH value, deposition potential, deposition time and material proportion were systematically investigated using square wave anodic stripping voltammetry (SWASV). The interferences from other ions on the target ion have also been discussed in this study. Under the optimal conditions, the GO/MnO2/GCE exhibited the linear ranges of 0.05 ∼ 1 μM for Cu(II) and Pb(II) with the detection limits of 1.67 nM and 3.33 nM, respectively, which was much lower than some electrochemical methods in reported literatures. The work provides a novel, simple and fast method for the simultaneous determination of Cu(II) and Pb(II).

An Electrochemical Sensor Based on an Ionic Liquid Covalently Functionalized Graphene Oxide for Simultaneous Determination of Copper (II) and Antimony (III)

AbstractGraphene oxide (GO) was chemically grafted by ionic liquid (IL) containing amino groups for preparation of IL covalently functionalized GO (IL–CFGO). SEM, FTIR and XRD results confirmed that IL had been successfully anchored on GO surface, resulting in more active sites and higher conductivity. The IL–CFGO composite was coated on the surface of carbon IL electrode (CILE) to construct electrochemical sensor for simultaneous detection of Cu(II) and Sb(III). The experimental factors including pH, deposition time and potential were optimized. Differential pulse voltammetry was employed for the simultaneous determination of Cu(II) and Sb(III) under the optimal conditions. The IL–CFGO/CILE exhibited the wide linear ranges of 0.1∼28 μM for Cu(II) and 0.1∼20 μM for Sb(III) with detection limits of 0.04 and 0.06 μM, respectively. The proposed sensor displayed good reproducibility, selectivity and acceptable stability owing to the contributions of the more active sites and the enhanced conductivity.

Mesoporous CeO2 nanoparticles modified Glassy carbon electrode for individual and simultaneous determination of Cu(II) and Hg(II): Application to environmental samples

An electrochemical sensor based on the use of CeO2 nanoparticles modified glassy carbon electrode (CeO2/GCE) was prepared and applied for determination of Cu(II) and Hg(II) individually and simultaneously. The differential pulse anodic stripping voltammetry (DPASV) results indicates that the CeO2 NPs based sensor exhibits good electroanalytical performance with two well-resolved voltammetric stripping peaks for Cu(II) and Hg(II). The proposed CeO2 NPs based sensor shows a wide linear range from 10 to 350 µg/L and a lower detection limit (3σ) 2.9 for Cu(II) and 3.3 µg/L for Hg(II) under optimized conditions. The developed sensor was successfully applied for the quantification of Cu(II) and Hg(II) in real sample matrices, and satisfactory results were obtained.

Three-way DNA junction based platform forultra-sensitive fluorometric detectionof multiple metal ions as exemplified for Cu(II), Mg(II) and Pb(II).

A DNA-based fluorometric method is described for simultaneous determination of multiple metal ions. It is based on recycling cleavage of hairpins by using a three-way DNA junction structure. Three DNA sequences containing a binding region and an enzyme-strand (E-DNA) region are hybridized to form a three-way DNA junction. The enzyme strand regions at the end of the DNA sequence binds to the substrate sequence (S-DNA) at the loop of the hairpin to form typical DNAzyme structures. In the presence of analyte metal ions, the DNAzyme structure thus formed cleaves the loop of hairpins. This is accompanied by a release of fluorescently labeled DNA fragments and by quenching of fluorescence. The detection limits are 35 pM for Cu(II), 2nM for Mg(II), and 8 pM for Pb(II). This method was successfully applied to the simultaneous determination of these ions in spiked human serum. Graphical abstract Schematic presentation of the recycling cleavage of hairpins by using a three-way DNA junction structure. It causes a release of fluorescently labeled DNA fragments and quenching of fluorescence. It was successfully applied to the simultaneous determination of Cu(II), Mg(II) and Pb(II) in spiked human serum.

Application of SBA-15/Diphenyl Carbazon/SDS Nanocomposite as Solid-Phase Extractor for Simultaneous Determination of Cu(II) and Zn(II) Ions

In the present study, trace quantities of copper(II) and zinc(II) ions in natural water, herbal and food samples was separated, preconcentrated and determined by a new nanocomposite. The nanocomposite was prepared by immobilization of diphenylcarbazone on SBA-15 nanoparticles coated with anionic surfactant sodium dodecyl sulfate. In order to investigate the effectiveness and size of the surface, SBA-15 nanoparticles and nanocomposites were analyzed by Brunauer–Emmett–Teller technique, transmission electron microscope, elemental analysis map, energy-dispersive X-ray spectroscopy, thermogravimetric analysis and elemental analysis CHNS. The effective factors such as pH, adsorbent amount, extraction time, eluent concentration and acid recovery volume were investigated and optimized for quantitative determination of Cu(II) and Zn(II) ions. Figures of merit such as precision, accuracy, limit of detection, enhancement factor and enrichment factor were obtained with good results. The linear range of the calibration graph was between 0.5 and 100 ng $$\hbox {mL}^{-1}$$ for Cu(II) and between 1 and 500 ng $$\hbox {mL}^{-1}$$ for Zn(II), and the detection limit was calculated to be 0.21 and $$0.93\,\hbox {ng} \,\hbox {mL}^{-1}$$ , respectively. Relative standard deviations of Cu and Zn were calculated to be 1.54 and 1.31%, respectively.

Utilization of AuNPs dotted S-doped carbon nanoflakes as electrochemical sensing platform for simultaneous determination of Cu (II) and Hg (II)

Gold nanoparticles (AuNPs) dotted S-doped carbon (AuNPs/S-C) nanoflakes were synthesized via a facial and simple approach. Typical synthesis route involves the formation of gold nanoparticles/poly(3,4-ethylenedioxythiophene) (AuNPs/PEDOT) and a subsequent calcination process. Many techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) were used to characterize their morphology, structures and compositions. Results indicated that AuNPs with an average size of 5nm were uniformly dotted on/into the S-C nanoflakes. The AuNPs/S-C/nafion was utilized as a new electrode material for simultaneously electrochemical determination of Cu (II) and Hg (II) using differential pulse anodic stripping voltammetry (DPASV) technique. Benefiting from the efficient metal-complexing ability and electrocatalytic activity of S-C and the good conductivity of AuNPs, the modified electrode exhibited enhanced electrochemical performance compared with bare glassy carbon electrode. Under optimal conditions, the peak currents displayed linear response to the concentrations of Cu (II) and Hg (II) ranges from 0.64 to 63.55μg/L and 4.01 to 300.89μg/L, with detection limits of 0.19μg/L and 1.40μg/L (S/N=3), respectively. The modified electrode was also applied for the determination of Cu (II) and Hg (II) in lake water samples with good results.

Development and validation of HPTLC method for simultaneous estimation of curcumin and galangin in polyherbal capsule dosage form

Simple and precise HPTLC methods were developed for the simultaneous estimation of two anti-inflammatory drugs (curcumin and galangin). The method was tailored to analyze both drugs in their commercial dosage form (capsules) with no interference from ingredients. Chromatographic separation was performed over precoated TLC plates (60 F254, 20cm×10cm, 250μm thickness, Merck, Darmstadt, Germany) via a linear ascending technique using n-hexane, ethyl acetate, acetic acid, and methanol as the mobile phase. Detection and quantification was achieved at 404nm through spectro-densitometric analysis. Analytical performance of the proposed HPTLC method was validated according to the ICH guidelines with respect to the linearity, accuracy, precision, detection and quantitation limits, robustness and specificity. The calibration curves were linear with the limits of 80–450 and 200–1200ng/spot for CU and GA, respectively, with correlation coefficients (r2) >0.9998. The limits of detection were 18.31 and 40.50ng/spot for CU and GA, respectively. The validated HPTLC method was successfully applied to the simultaneous determination of CU and GA in the commercial polyherbal formulation.

H-point Standard Addition Method (HPSAM) for Simultaneous Spectrophotometric Determination of Cu(II) and Pd(II) by 1-(2-thiazolylazo)-2-naphthol (TAN) in Micellar Media

The H-point standard addition method (HPSAM) is proposed for the simultaneous determination of Cu(II) and Pd(II). It is a simple, selective, and sensitive, spectrophotometric method. The basis of this technique is the complex formation of Cu(II) and Pd(II) with 1-(2-thiazolylazo)-2-naphthol (TAN) at pH 2.2, and in the presence of sodium dodecyl sulfate (SDS) as a micellizing agent. The sensitivity and selectivity of the method improve in the presence of a micellar system and an acidic medium, respectively. Cu(II) and Pd(II) can be determined in the concentration ranges of 0.04-3.40 and 0.12-6.0 μg mL-1 with satisfactory accuracy and precision. The proposed method was used for the simultaneous determination of Cu(II) and Pd(II) in water and various synthetic alloy samples with different concentration ratios of Cu(II) and Pd(II) with good accuracy and precision.

Contribution to diagnostics/prognostics of tuberculosis in children. I. New methods of assaying zinc and simultaneously copper and zinc in diluted sera by flame atomic-absorption spectrometry.

In an attempt to provide a reliable status of metal ions in children, new methods of analysis of children's sera are proposed. New flame atomic-absorption spectrometric (FAAS) methods are simple, cost- and time-effective and, above all, labor-, reagent- and sample-saving. Two methods were suggested: method A for simultaneous determination of Cu and Zn from 5-fold diluted sera, and method B, for assaying zinc alone in 10-fold diluted samples. Both methods are based on a single-step sample pretreatment (deproteinization with 3 mol dm-3 HCl). Method A uses a single-step calibration with a mixed standard. The main advantage of method B is an additional reduction in sample consumption. Both methods were fully validated against reference methods. Accuracy, sensitivity and precision have proven them to be comparable to the reference methods in terms of analytical performance, and applicable to analyses of children's sera.

Construction of Modified Carbon Paste Electrode for Highly Sensitive Simultaneous Electrochemical Determination of Trace Amounts of Copper (II) and Cadmium (II)

AbstractA chemically modified electrode was constructed for rapid, simple, accurate, selective and highly sensitive simultaneous determination of Cu(II) and Cd(II) using square wave anodic stripping voltammetry. The electrode was prepared by incorporation of SiO2 nanoparticles, coated with a newly synthesized Schiff base, in carbon paste electrode. The limit of detection was found to be 0.28 ng mL−1 and 0.54 ng mL−1 for Cu(II) and Cd(II), respectively. The proposed chemically modified electrode was used for the determination of copper and cadmium in several foodstuffs and water samples.

Simultaneous determination of Cu, Pb, Cd, Ni, Co and Zn in bioethanol fuel by adsorptive stripping voltammetry and multivariate linear regression

In this work it is proposed the one-voltammogram simultaneous determination of Cu(II), Pb(II), Cd(II), Ni(II), Co(II), and Zn(II) at ppb and sub-ppb levels in bioethanol fuel samples by adsorptive stripping voltammetry. Mixed ligands were employed providing stripping peaks for all analytes at the same voltammetric scan under optimized conditions. To perform the determination, multivariate linear regression aided by successive projections algorithm (SPA–MLR) was evaluated. The voltammograms were preprocessed with the asymmetric least squares (AsLS) baseline correction algorithm and the icoshift peak alignment tool. An excellent analytical performance was obtained, despite the inherent complexity of the simultaneous determination, with average apparent recovery=96%±16%, and better prediction results in comparison with the benchmark method of partial least squares (PLS).

Effectively simultaneous naked-eye detection of Cu(II), Pb(II), Al(III) and Fe(III) using cyanidin extracted from red cabbage as chelating agent

Simultaneous determination of Cu(II), Pb(II), Al(III) and Fe(III) using cyanidin as a chelating agent was investigated in terms of both quantitative and qualitative detections. Cyanidin was extracted and purified from red cabbage which is a local plant in Thailand. The selectivity of this method was examined by regulating the pH of cyanidin solution operated together with masking agents. It was found that Cu(II), Pb(II), Al(III) and Fe(III) simultaneously responded with the color change at pH 7, pH 6, pH 5 and pH 4, respectively. KF, DMG and the mixture of KF and DMG were used as masking agents for the determination of Fe(III), Al(III) and Pb(II), respectively. Results from naked-eye detection were evaluated by comparing with those of inductively coupled plasma (ICP), and there was no significant difference noticed. Cyanidin using as a multianalyte reagent could be employed for simultaneous determination of Cu(II), Pb(II), Al(III) and Fe(III) at the lowest concentration at 50, 80, 50 and 200μM, respectively, by slightly varying pHs. Moreover, the proposed method could be potentially applied for real water samples with simplicity, rapidity, low cost and environmental safety.