Method For Determination Of Copper Research Articles

Development of a metal sieve-linked double syringe liquid phase microextraction method for the determination of copper in olive leaf extract samples by flame atomic absorption spectrometry

This work reports the development of a simple, sensitive and low-cost analytical method for the trace determination of copper. A metal sieve-linked double syringe liquid phase microextraction method was used to preconcentrate copper into measurable quantities for FAAS system. The pressurized mixing offered by the automated syringe system and the sieve connector enhanced surface area for analyte and extraction solvent interaction, this significantly increased the extraction efficiency for copper. There was therefore no need for auxiliary organic solvents as disperser solvents for the extractant dichloromethane. The limits of detection and quantification, linear dynamic range and percent relative standard deviation values calculated for copper under optimum conditions of the method were 1.5 and 5.1 µg L−1, 5.0–500 µg L−1 and 8.4%, respectively. The developed method was successfully employed to determine copper (0.75–8.06 mg kg−1) in unspiked olive leaf samples.

An eco-friendly, sensitive and selective derivative spectrophotometric method for simultaneous determination of copper and zinc in synthetic mixtures, alloys and environmental samples

ABSTRACT This article proposes a cost-effective and green sensitive derivative spectrophotometric method for simultaneous determination of two essential elements, copper and zinc as their complexes with 2-(5-Bromo-2-pyridylazo)-5-diethyl-aminophenol in presence of a cationic micellar medium. The analytical sensitivity and molar absorption coefficient of the 1∶2 Cu(II)–5-Br-PADAP complex in cationic micellar media are 1.30 × 10–2 ng mL−1 and 1.10 × 105 L mol−1 cm−1, respectively. Beer’s law is obeyed in the concentration range from 3.20 × 10–2 to 8.32 × 10–1 µg mL−1 and the limit of detection of Cu(II) is 3.80 × 10–2 ng mL−1. The satisfactory results are obtained for the determination of Cu(II) in derivative modes, with a relative standard deviation of 1.44% (n = 6). In normal mode, the determination of Cu(II) and Zn(II) in presence of each other is difficult because of their overlapping absorption spectral profiles. In second-order derivative mode, 1.28 × 10–1 – 8.32 × 10–1 µg mL−1 of Cu(II) and 6.50 × 10–2 – 6.50 × 10–1 µg mL−1 of Zn(II) can be simultaneously determined at zero cross-over point of Zn(II) and Cu(II) complexes, respectively, when present together without any prior time consuming extraction/separation steps using toxic organic solvents. The proposed rapid and selective derivative spectrophotometric method has been successfully assessed for simultaneous determination of copper and zinc in synthetic mixtures, alloys, and environmental samples.

Multivariate optimization of a dispersive liquid-liquid microextraction method for determination of copper and manganese in coconut water by FAAS

In this study, multivariate methodologies were applied in the optimization of a dispersive liquid–liquid microextraction (DLLME) method, aiming at the determination of Cu and Mn in coconut water samples by flame atomic absorption spectrometry. Some extractors (chloroform and CCl4), dispersants (ethanol, methanol and acetonitrile) and complexing agents (5-Br-PADAP and Dithzone) were previously tested in the extraction. A mixture design was used to optimize the component proportions formed by chloroform (10%), acetonitrile (76%), and 0.020% 5-Br-PADAP solution (14%). Doehlert design optimized the variables pH, NaCl, and buffer amounts for the extraction of both metals. The following analytical characteristics, respectively for Cu and Mn, were accessed: limit of quantification (4.83 and 3.32 µg L−1), enrichment factors (11 and 8 fold), and precision (6.6 and 6.0% RSD, n = 10). Addition/recovery tests of the analytes allowed to find values in the range of 96.5–120% for Cu and 99–107% for Mn.

2-chlorobenzaldehyde thiocarbohydrazone: a novel reagent for liquid-liquid extractive spectrophotometric determination of copper(II) from environmental and real samples

ABSTRACT 2-Chlorobenzaldehyde thiocarbohydrazone (2-CBTCH) is proved as a novel analytical chelating reagent to developa simple, fast and selective liquid–liquid extractive spectrophotometric method for trace level determination of copper(II). The method was based upon the complexation reaction of copper(II) with 2-CBTCH in ethanol. It instantly forms orange coloured [Cu(II)-2 CBTCH] complex at room temperature, which was quantitatively extracted in 1-butanol and shows maximum absorption at 470 nm. The values of molar absorptivity and Sandell’s sensitivity of [Cu(II)-2CBTCH] complex are found to be 0.3429 × 104 Lmol−1 cm−1 and 0.01851 µgcm−2, respectively. The system follows Beer’s law up to 17.5 µgmL−1. The stoichiometry of the [Cu(II)-2CBTCH] complex in 1-butanol is determined by Job’s method, mole ratio method is 1:2 and was confirmed by log-log plot method. To intuit the peak extraction conditions several experimental factors such as pH, reagent concentration, selection of solvent, shaking time, interference of cations and anions has been studiedwell. The usage of masking agent lifts the selectivity of the present method. The method has been effectively used for the determination of copper(II) in alloy samples, pharmaceutical samples, fertiliser samples and environmental samples such as leafy vegetables and water samples.

Determination of copper in edible oils by direct graphite furnace atomic absorption spectrometry

A simple method for determination of copper in edible oils was developed, using a polarized Zeeman graphite furnace atomic absorption spectrophotometer and a pyro graphite tube. Edible oils were diluted with 2% lecithin-cyclohexane and analyzed directly by the standard addition method. The optimal ashing and atomizing temperatures were 900°C and 2700°C, respectively. A standard solution diluted with 2% lecithin-cyclohexane was superior to salad oil or cyclohexane. Results were best measured when the concentration of lecithin in cyclohexane was higher than 2%. The detection limit of this method was 2.0 ng/mL. The respective range of recovery of copper was 85.5-90.0% and 86.0-93.0% in salad oil and lard which were fortified with 10, 20 and 40 ng Cu/mL respectively using the standard addition method.

Modern Eco-Analytical Extraction-Spectrophotometric Method for Copper Determination with 1-(2-Pyridylazo)2-Naphthol (PAN)

A method for the extraction-spectrophotometric determination of copper with PAN is developed. This method differs from the existing approaches in selectivity, sensitivity, simplicity, and rapidity. It is recommended to analyze ores, concentrates, industrial solutions, and wastewater, as well as materials of complex chemical composition without the separation of accompanying ions directly in the organic phase.

A simple non-extractive green method for the spectrophotometric sequential injection determination of copper(ii) with novel thiazolylazo dyes.

This work introduces two new thiazolylazo dyes 1-[(5-benzyl-1,3-thiazol-2-yl)diazenyl]naphthalene-2-ol (BnTAN) and 1-[5-(4-sulfonamidobenzyl-4-methyl-1,3-thiazol-2-yl)diazenyl]naphthalen-2-ol (SABnMeTAN) as possible reagents for spectrophotometric determination of copper(ii) in water samples in the form of a chelate complex. The substances were synthesized for the first time and characterized using the NMR technique. The main characteristics of ligands, such as molar absorption coefficients and protonation constants, were evaluated spectrophotometrically. A non-extractive sequential injection spectrophotometric method for the determination of copper(ii) in the presence of Triton X-100 was developed. The linear range of the calibration plot was observed from 0.063 to 1.270 mg L−1 and the detection limit was 0.044 mg L−1. The SIA method was compared with the respective manual method and applied for the determination of copper(ii) in tap and river water.

Mixed-ligand complexes of copper (II) with ditiolfenols and heterocyclic diamines

By the methods spectrophotometric methods was investigated complex formation of copper with 2,6-ditiolphenol and its derivatives (2,6-ditiol-4-methylphenol, 2,6-ditiol-4-ethylphenol and 2,6-ditiol-4-tert-buthylphenol) in the presence of heterocyclic diamines. As heterocyclic diamines phenantroline (Fen), batophenantroline and dipyridile were used. It was established, that mixedligand complex were formed in weak acidic medium (pHop=6,0-8,5). Maximum of light absorption observed at (=522–550 nm. Molar coefficient of light absorption was ( = (3.08–4.92)?104. The stoichiometry of complexes had been discovered using shift the equilibrium and relative yield methods. During the extraction of copper(II) complexes with ditiol-phenols with the presence of heterocyclic diamines there was discovered that there is no chlorophorm molecules in the composition of the extracted complexes. IR spectra shows that hydroxyl group is involved to the formation of a bond with the metal and that phenantroline is included in the composition of the copper complex. In the organic phase mixed-ligand complexes have the monomeric form and can’t polymerize; that fact can be proved by calculations. By dint of spectrophotometric, IR-spectroscopic, thermogravimetric experiments and some published data we were able to determine the structural formula of complexes. Also had been determined main spectrophotometric characteristics of copper(II) mixed-ligand complexes: pH of the beginning of the deposition, optimal pH, detection limit and sensivity. For separation and finding copper, we studied the effect of interfering foreign ions: alkali, alkaline earth and rare earth elements, as well as acid anions selected masking reagents. On the base of the results was offered photometric method for determination of copper in steel different trade-marks and in food. This method characterized by good reproduction (relatively standard deviation no more 0.05) and low limit of discovery.

SPECTROPHOTOMETRİC STUDY OF THE COMPLEX FORMATİON OF COPPER (II) WİTH 1-PHENYL-2- [2-HYDROXY-3-SULFO-5-NİTROPHENYLAZO] 1,3-BUTADİONE İN THE PRESENCE OF CATİONİC SURFACTANTS.

Based on benzoylacetone synthesized 1-phenyl-2- [2-hydroxy-3-sulfo-5-nitrophenylazo] 1,3-butadione (PHSNPAB). Studied complex formation of copper (II) with 1-phenyl-2- [2-hydroxy-3-sulfo-5-nitrophenylazo] 1,3-butadione (PHSNPAB) in the presence and absence of the third component such as cetylpyridinium chloride (CPCl), cetylpyridinium bromide (CPBr) and cetyltrimethylammonium bromide (CTMABr). Single ligand complexes are formed at pH = 3, λ = 444nm, and mixed ligand complexes at pH = 2 λ = 456, 454, and 461 nm, respectively (CPCl, and CPBr, CTMABr). İdentified the relations of the reacting components in homogeneous composition of Cu-R (1: 2) and mixed ligand Cu-R-CPCl (1: 2: 2), Cu-R-CPBr (1: 2: 2) and Cu-R-CTMABr (1 2: 1) complexes, which concentration interval subordinated to Beer's law. The influence of external ions and masking substances on complex formation was studied. Method for the photometric determination of copper in the rocks was established.

A novel method for determination of copper in zinc destined to 64Cu production in a nuclear reactor

The assay of copper in zinc matrixes by reactor activation analysis presents significant difficulties, since the practicable capture reactions, 63Cu(n,γ)64Cu and 65Cu(n,γ)66Cu, are interfered by 64Zn(n,p)64Cu and 66Zn(n,p)66Cu reactions, as dominant activities. Taking into account this fact, the possibility of developing a method for copper determination in zinc compounds based on the measurement of 66Cu/64Cu activity ratios is discussed. The theoretical fundamentals are formulated; the experimental application for the application to the control of zinc compounds destined to the production of 64Cu is described.

Optimization of Digestion Method for Determination of Copper in Shrimp Paste Sample Using Flame Atomic Absorption Spectrometry

Optimization of Digestion Method for Determination of Copper in Shrimp Paste Sample Using Flame Atomic Absorption Spectrometry

A simple and green analytical method for determination of copper(ii) in whisky and sugarcane spirit by diffuse reflectance spectroscopy

In this paper we propose a new, fast, simple, economical, portable and environmentally friendly analytical methodology for the determination of copper(ii) ions in whisky and sugarcane spirit, using the combination of spot-test and diffuse reflectance spectroscopy.

Optimization of an analytical method for the spectrophotometric determination of copper in tea and water samples after ultrasonic assisted cloud point extraction using a benzothiazole fluorescein derivative complexing agent

BTF is exists with spirolactone species with adding Cu2+, which leads to the absorbance intensity is decreased gradually and the decrease of the absorbance value is linear for Cu2+.

Determination of copper in whole blood by differential pulse adsorptive stripping voltammetry

 A selective and sensitive method for determination of copper in blood by adsorptive differential pulse cathodic stripping voltammetry is presented. The method is based on adsorptive accumulation of the complexes of Cu (II) ions with benzenesulfonyl hydrazide onto hanging mercury drop electrode (HMDE), followed by the reduction of the adsorbed species by differential pulse cathodic stripping voltammetry. The effect of various parameters such as supporting electrolyte, concentration of benzenesulfonyl hydrazide, accumulation potential, accumulation time and stirring rate on the selectivity and sensitivity were studied. The optimum conditions for determination of copper include perchloric acid 0.03 M, concentration of benzenesulfonyl hydrazide 7.5×10-5 M, the accumulation potential of -350 mV (vs. Ag/AgCl), the accumulation time of 50 s, and the scan rate of 50 mV s-1. Under optimized conditions, linear calibration curves were established for the concentration of Cu (II) in the range of 0.62-275 ng mL-1, with detection limit of 0.186 ng mL-1 for Cu (II). The procedure was successfully applied to the determination of copper ion in whole blood samples.

An automated in-chip-catalytic–spectrophotometric method for determination of copper(ii) using a multisyringe flow injection analysis-multipumping flow system

An automated in-chip-catalytic–spectrophotometric method for determination of copper(ii) using a multisyringe flow injection analysis-multipumping flow system (Chip–MSFIA–MPFS).

Increased Sensitivity Spectrophotometric Flow Analysis Method for Copper Determination in Water Samples

A reverse configured flow injection system was developed for the determination of copper in water samples. In this study, a bathocuproine disulfonic acid copper complexing reagent was used. In the presence of a reducing agent (hydroxylamine), the formation of complex was monitored at 484 nm. The determination range extended from 1 to 40 µg L−1, with an applicable determination rate of 40 h−1. The developed method was applied to the determination of copper in water samples (estuarine, river, and drinking water) and showed good accuracy (z-score below 2). The detection limit of 0.7 µg L−1 copper is consistent with the requirement of the target water samples. The developed method was also used for the comparison of different spectrophotometric flow cells. Alternative flow cells (U, Z shaped, and the liquid waveguide capillary cell) were compared in terms of their sensitivity and response to refractive index changes.

Label-free selective impedimetric detection of Cu2+ ions using catalytic DNA

Copper is an essential element for regulation of many biological processes, however, in excess it is considered to be toxic for human health. This metal is frequently accompanied by other elements such as cadmium, nickel and lead. Thus, developing a selective and simple method for determination of copper in a matrix containing other heavy metal ions is of great importance. In this work, a novel selective method for copper detection was developed using electrodes modified with the DNAzyme capturing Cu(2+) ions. The DNAzyme reconstituted with copper catalyzes oxidation of ascorbic acid leading to the build-up and adsorption of oxidation products on the electrode surface and produces changes in the interfacial properties of the electrode. The increase in the interfacial electron-transfer resistance is probed with electrochemical impedance spectroscopy (EIS) in the presence of the reversible redox couple [Fe(CN)6](3-)/[Fe(CN)6](4-) as a marker. The DNAzyme based biosensor combines excellent selectivity against other heavy metal ions with sufficient sensitivity to Cu(2+) in the range of 6.5-40 μM.

Colorimetric sensing of copper(ii) based on catalytic etching of gold nanorods

In this work, a sensitive colorimetric method for determination of copper(II) in aqueous solution was developed based on catalytic etching of gold nanorods (GNRs). CTAB stabilized GNRs were etched slowly by dissolved oxygen along the axial direction in NH3–NH4Cl (0.8/0.1 M) solution. The etching was accelerated by the addition of Cu2+ with very low concentration, leading to a dramatic decrease of the GNRs in length but little in diameter. The etching caused the longitudinal surface plasmon resonance (LSPR) absorption to decrease sharply and shift to the short-wave direction, accompanied by a color change from blue to slight red. Potential effects of relevant experimental conditions, including concentrations of NH3 and S2O32−, and incubation temperature and time were evaluated for optimization of the method. The proposed method is sensitive (LOD = 2.7 nM) and selective (by at least 100-fold over other metal ions except for Mn2+ and Pb2+) with a linear range from 7 to 50 nM. Furthermore, the cost-effective method allows rapid and simple determination of the content of copper in shellfish samples.

Determination of Trace Amounts of Copper (I) in Water and Soil Samples Using Directly Suspended Droplet Microextraction-flame Atomic Absorption Spectrometry (DSDME-FAAS)

In this study a highly simple and sensitive spectrometric method for determination of copper (II) is proposed. Neocuproine hydrocholoride (NC) was used as a complexing agent and a new preconcentration method, termed directly suspended droplet solvent microextraction (DSDME), was developed. In this technique, a free microdroplet of organic solvent is delivered to the surface of an immiscible aqueous sample. When extraction is completed, a portion of the organic phase is sampled with a micro pipette and its copper content determined by flame atomic absorption spectrometry. Some effective parameters on extraction and complex formation such as pH, the kind and volume of organic solvent, extraction time, stirring rate, were optimized. Under the optimum conditions, the enrichment factor of 52.42 and recovery of 98.06 were obtained. The calibration curve was linear in the range of 0.008–0.24 mg L–1 (8.0–240μg L–1)with detection limit of 0.83 μg L–1. The relative standard deviations for six replicate determinations of 0.008, 0.072, and 0.144 mg L–1 of copper were 6.13 %, 3.69 %, 2.78 % respectively. Also, the effect of foreign species was investigated.

Environmental method for spectrophotometric determination of copper(II)

A highly stable ternary complex of copper(II) with 5-(4-nitrophenylazo) salicylic acid (NPAS) and 2,2′-Dipyridyl (Dp) in ethanol medium at room temperature gave a maximum absorption at 520 nm with a molar absorptivity 2.60×104 L mol-1 cm-1. This method was characterized by safety to the environment as there are no uses of hazardous solvents, which may harm our environment. The linear range for copper determination was 2.2–6.3 mg L-1. The method was sensitive, accurate, and tolerant to many foreign ions. All the reagents were stable under the working conditions. Moreover, the method was easy to perform for the determination of copper in pharmaceutical, biological, and water samples.