Determination Of Copper In Seawater Research Articles

A novel stainless steel needle electrode based on porous gold nanomaterials for the determination of copper in seawater

A stainless-steel needle electrode modified with porous gold and partially sacrificed polydopamine nanospheres was fabricated for the copper detection in seawater.

Voltammetric determination of copper in seawater at aglassy carbon disk electrode modified withAu@MnO2 core-shell microspheres.

Anodic stripping voltammetric determination of copper ions was accomplished at a glassy carbon disk electrode modified with core-shell microspheres of the gold@manganese dioxide (Au@MnO2) type. These were synthesized via electrochemical deposition. The gold nanoparticles (AuNPs) were electrochemically deposited and employed as an active support material for the growth of MnO2 to yield Au@MnO2 core-shell particles with unique and regular spherical morphology. The microspheres have a diameter of 200-250nm and scrolled edges like a cactus. Due to the absorption capacity of MnO2 and the electrocatalytic ability of the AuNPs, an excellent anodic signal is obtained for copper ions. Response is linear in the 20nM to 1μM copper ion concentration range, with a 4.9 ± 0.2nM (n= 3) detection limit under optimized conditions. The electrode is stable and excellently reproducible. It was successfully applied to the analysis of copper ions in spiked seawater samples. Graphical abstract Gold nanoparticles were employed as a coupling medium for the bridging of MnO2 on a glassy carbon disk electrode to transfer electrons that enhanced electrochemical detection of copper ions.

Determination of Copper in Seawater Using a Sequential Injection System Incorporating a Sample Pretreatment Module Coupled to Electrothermal Atomic Absorption Spectrometry

An automated sequential injection system incorporating a sample pretreatment module was developed for the separation and preconcentration of ultra-trace copper in seawater without dilution. Cu-PDC (pyrrolidine dithiocarbamate) chelate was retained in a PTFE-beads-packed column in the module, which was later eluted with a small amount of methanol, and the eluate was quantified using electrothermal atomic absorption spectrometry (ETAAS). An enrichment factor of 20, a limit detection of 0.015 μg l −1, and a sampling frequency of 26 per hour were obtained with a sampling volume of 1.0 ml within the concentration range of 0.05–1.00 μg l −1, achieving a precision of 1.8% RSD ( n = 7) at the level of 0.50 μg l −1. The system was validated by analyzing a certified reference material of seawater, NASS-5, and was further demonstrated by spiking recoveries in a coastal seawater sample employing various dilution factors.

Determination of copper in seawater based on a liquid membrane preconcentration system

A new method to determine the concentration of copper in seawater has been developed. It was based on the use of a bulk liquid membrane (BLM) system to separate and preconcentrate the copper ions, allowing the use of a very simple and common analytical technique as flame atomic absorption spectroscopy (FAAS). The liquid membrane consisted of an organic solution containing di-(2-ethylhexyl)phosphoric acid (DEHPA) in kerosene. The chemical optimization of the preconcentration system was performed by using the modified simplex method. Under optimum conditions, the preconcentration yield for real samples was 76.21%, copper preconcentration factor being 4.30. The reliability of the new method was confirmed by analyzing several real seawater samples, with copper concentrations ranging between 2.5 and 5 μg l −1 , previously analyzed by a well-established technique. For these real samples, the average relative error of the determination was 9.96%, while relative standard deviation averaged 0.33%.

The determination of copper at thin film electrodes by constant current stripping potentiometry

AbstractA comparison of the determination of copper by constant current stripping potentiometry (CCSP) at mercury and gold films has been carried out. The preferred solution conditions for the mercury film study were determined to be 0.1M ammonium acetate at pH 4.5 and 0.1M HCl for the gold film study. The influence of chloride on the stripping signal was investigated and it was found that for the mercury film conditions, well‐formed stripping signals could be obtained up to a chloride concentration of 0.5 M which permitted the ready determination of copper in seawater. With the gold film, high chloride concentrations affected both the film stability and the glassy carbon surface and repeatable results were difficult to obtain. The optimized CCSP methods were applied to various aqueous samples including tap water, seawater, TCLP (acetic acid) extracts as well as TCLP extracts using groundwater and ocean water. Based on the results obtained for these various matrices, it was concluded that there are several advantages favoring the mercury film. The interference from organic components in the sample matrix on the general applicability of CCSP for the determination of copper at either a mercury or gold film is discussed.

Determination of copper in seawater by adsorptive voltammetry with 1,2‐dihydroxyanthraquinone‐3‐sulfonic acid

AbstractA method is described for the determination of copper in seawater by adsorptive stripping voltammetry after accumulation of a 1,2‐dihydroxyanthraquinone‐3‐sulfonic acid (DASA) complex. The effects of various operational parameters (pH, ligand concentration, potential, and accumulation time) on the reduction current of the adsorbed chelate are discussed. A linear current concentration relationship was observed up to 5 × 10−8 M. The detection limit is 0.3 nM.

Direct determination of copper in sea-water with a graphite furnace atomic absorption spectrometer

Copper in sea-water was determined directly using a graphite furnace atomic absorption spectrometer (GFAAS) with a stabilized temperature platform and matrix modification through addition of ammonium nitrate. Both deuterium background correction and Zeeman effect background correction were used and compared. The detection limit was 0.3–0.4 μg l with injection of a 20 μl aliquot of sea-water sample. The matrix interference was removed completely, so that a calibration curve using deionized water could be used. The detection limit was further reduced to 0.07 μg l using multiple injection (injection of five 20 μl aliquots of sea-water). The accuracy and precision of the developed methods were confirmed by analysis of three kinds of certified reference sea-water.

Determination of copper in seawater by anodic stripping voltammetry using ethylenediamine

On utilise la voltammetrie de redissolution anodique avec une electrode a goutte de mercure pendante pour detecter le cuivre dans l'eau de mer a une teneur de 5×10 −10 M. Presentation d'une technique pour mesurer le cuivre labile et echangeable avec les ligands a pH 8

Determination of copper in seawater by anodic stripping voltammetry using ethylenediamine: Scarano, Gioacchino, Elisabetta Morelli, Alfredo Seritti and Alberto Zirino, 1990. Analyt. Chem., 62(9):943–948. Zirino: Mar. Environ. Br., Code 522, Naval Ocean Syst. Ctr., San Diego, CA 92152

Determination of copper in seawater by anodic stripping voltammetry using ethylenediamine: Scarano, Gioacchino, Elisabetta Morelli, Alfredo Seritti and Alberto Zirino, 1990. Analyt. Chem., 62(9):943–948. Zirino: Mar. Environ. Br., Code 522, Naval Ocean Syst. Ctr., San Diego, CA 92152

Determination of copper in seawater by high-temperature gas chromatography with an atomic absorption spectrometric detector

A high-temperature gas-chromatographic system was applied to the determination of copper in artificial seawater.

Preparation and analytical properties of a chelating resin containing phenylalanine groups

A polystyrene-based macroreticular resin containing phenylalanine groups has been prepared and its analytical properties have been investigated and compared with Dowex A-1. The phenylalanine resin shows high selectivity for mercury(II) and copper(II) in the pH region 2–3. The sorption behaviour of copper has been examined in detail, with the intention of using the resin analytically. The important characteristics of the resin are fast equilibration, high selectivity and small volume change between its hydrogen form and metal forms. These enable it to be applied for the rapid concentration of trace amounts of copper in the presence of large amounts of diverse metals. It may be used for the determination of copper in sea-water and the separation of copper/cobalt and copper/nickel.

Dual-wavelength spectrophotometric determination of copper in sea-water with α,β,γ,°-tetrakis(1-methylpyridinium-4-yl) porphine

Copper has been determined by dual-wavelength spectrophotometry with α,β,γ,°-tetrakis(1-methylpyridinium-4-yl) porphine (TMPyP). The difference in absorbance at the Soret band of the copper complex (423 nm) and that of TMPyP (446 nm) was measured. Copper in a coastal sea-water sample was preconcentrated with a Chelex-100 separation in which l-cysteine was used as eluent. This combination could determine copper at the ng/ml and sub-ng/ml level.

Determination of copper in seawater by anodic stripping voltammetry

Copper in surface seawater has been determined using both hanging mercury drop and thin film electrodes. Total copper was found to be in the range 0.4–0.7 μg l −1 , and labile copper in the range 0.2–0.4 μg l −1 . Most of the copper present in seawater is complexed with or adsorbed on organic matter, and a smaller percentage is associated with inorganic colloids. Seawater contains both organic and inorganic compounds which will react with approximately 1×10 −8 M added ionic copper. Because of the presence of the complexing agents, peak current-copper concentration calibration curves in seawater are non-linear, and care must be exercised in using spiked results in the calculation of the copper content. The thin film electrode (TFE) is more suitable than the hanging mercury drop electrode for determining copper in seawater, although the TFE results are more dependent on deposition potential, and suffer from interference by nickel if very negative deposition potentials are used.

Determination of copper in seawater by anodic stripping voltammetry

Copper in surface seawater has been determined using both hanging mercury drop and thin film electrodes. Total copper was found to be in the range 0.4–0.7 μg l −1, and labile copper in the range 0.2–0.4 μg l −1. Most of the copper present in seawater is complexed with or adsorbed on organic matter, and a smaller percentage is associated with inorganic colloids. Seawater contains both organic and inorganic compounds which will react with approximately 1×10 −8 M added ionic copper. Because of the presence of the complexing agents, peak current-copper concentration calibration curves in seawater are non-linear, and care must be exercised in using spiked results in the calculation of the copper content. The thin film electrode (TFE) is more suitable than the hanging mercury drop electrode for determining copper in seawater, although the TFE results are more dependent on deposition potential, and suffer from interference by nickel if very negative deposition potentials are used.