Absorption Spectrometric Determination Of Copper Research Articles

Effervescence-assisted dispersive liquid-liquid microextraction based on deep eutectic solvent for preconcentration and FAAS determination of copper in aqueous samples

ABSTRACTA new effervescence-assisted dispersive liquid-liquid microextraction, EA-DLLME, technique was developed for preconcentration and flame atomic absorption spectrometric determination of copper in aqueous samples. Effervescence assistance and DES combination for metal ion extraction was used for the first time. In the presented study, six different effervescence powders were examined to achieve maximum extraction efficiency. In addition, 1,5 diphenyl carbazide was used as complexing agent and DES prepared by mixing choline chloride and phenol was used as extraction solvent. The effect of several parameters such as pH, concentration of complexing agent, composition and volume of DES, amount of THF, composition and amount of effervescent agent were examined. Performed experiments showed that optimum pH was 6.0, the best effervesce powder composition was NaH2PO4:Na2CO3 with 2 × 10−3:1 × 10−3 molar ratio and the amount of effervesce powder was 0.4 g. Under optimum conditions enhancement factor, limit of detection and limit of quantification were calculated as 78, 2.9 and 9.7 μg L−1, respectively. In addition, to prove precision of the method intra-day relative standard deviations were calculated for 10 and 50 μg L−1 Cu2+ concentrations and found as 2.1% and 1.3%, respectively. The proposed method showed good linearity within the range of 10.0–100 μg L−1. Finally, proposed method was successfully applied to determination of copper traces in aqueous samples.

Flame atomic absorption spectrometric determination of copper, lead, and cadmium in Gastrodiae rhizoma samples after preconcentration using magnetic solid-phase extraction

ABSTRACTIn this research, ferroferric oxide nanoparticles were coated with silicon dioxide and further functionalized with alizarin complexone as the adsorbent of magnetic solid-phase extraction, thus aiming for extraction and preconcentration of heavy metals in Gastrodiae rhizoma samples. The determination of heavy metals was carried out by flame atomic absorption spectrometry. The results showed that the functionalized magnetic nanoparticles demonstrated higher extraction efficiency for copper, lead, and cadmium. The synthesized magnetic sorbents were characterized by transmission electron microscope, X-ray diffraction, and Fourier-transformed infrared spectra. Different parameters influencing the extraction efficiency including the amount of sorbent, sample pH, sorption time, solution volume, elution solvent, and reuse times were optimized. Under the optimal conditions, the method detection limit was 0.18, 0.25, and 0.12 µg/L for copper, lead, and cadmium, respectively. The proposed method was successfully applied to extract copper, lead, and cadmium in Gastrodiae rhizoma samples, and the recoveries of the samples ranged from 90.0 to 102.0% and relative standard deviations (n = 5) were in the range of 1.93–3.82%.

Flame atomic absorption spectrometric determination of copper, zinc and manganese after solid-phase extraction using 2,6-dichlorophenyl-3,3-bis(indolyl)methane loaded on Amberlite XAD-16

A simple and selective method for the determination of Cu2+, Zn2+ and Mn2+ ions in real samples by FAAS after solid-phase extraction was developed. The method is based on the sorption of metal ions on Amberlite XAD-16 modified by 3-((2,6-dichlorophenyl)(1H-indol-3-yl)methyl)-1H-indole (DCPIMI) at a pH of 5.0. The metal ions retained on solid phase by complexation with ligand were then eluted with 6mL of 4molL−1 nitric acid in acetone. In order to obtain a reversible uptake and elution of metal ions, the influence of flow rates of eluent and sample solution, ligand concentration and amount of surfactant and condition of elution solution was also investigated. A preconcentration factor of 225 was achieved by passing 1350mL of sample through the solid phase, while the limit of detection (LOD) of Cu2+, Zn2+ and Mn2+ ions were found to be 1.9, 1.5 and 2.6ngmL−1, respectively, and the corresponding precision at 20μgL−1 was 2.1%, 2.3%, 3.0%.

On-line sequential injection dispersive liquid–liquid microextraction system for flame atomic absorption spectrometric determination of copper and lead in water samples

A simple, sensitive and powerful on-line sequential injection (SI) dispersive liquid–liquid microextraction (DLLME) system was developed as an alternative approach for on-line metal preconcentration and separation, using extraction solvent at microlitre volume. The potentials of this novel schema, coupled to flame atomic absorption spectrometry (FAAS), were demonstrated for trace copper and lead determination in water samples. The stream of methanol (disperser solvent) containing 2.0% (v/v) xylene (extraction solvent) and 0.3% (m/v) ammonium diethyldithiophosphate (chelating agent) was merged on-line with the stream of sample (aqueous phase), resulting a cloudy mixture, which was consisted of fine droplets of the extraction solvent dispersed entirely into the aqueous phase. By this continuous process, metal chelating complexes were formed and extracted into the fine droplets of the extraction solvent. The hydrophobic droplets of organic phase were retained into a microcolumn packed with PTFE-turnings. A portion of 300 μL isobutylmethylketone was used for quantitative elution of the analytes, which transported directly to the nebulizer of FAAS. All the critical parameters of the system such as type of extraction solvent, flow-rate of disperser and sample, extraction time as well as the chemical parameters were studied. Under the optimum conditions the enhancement factor for copper and lead was 560 and 265, respectively. For copper, the detection limit and the precision (R.S.D.) were 0.04 μg L −1 and 2.1% at 2.0 μg L −1 Cu(II), respectively, while for lead were 0.54 μg L −1 and 1.9% at 30.0 μg L −1 Pb(II), respectively. The developed method was evaluated by analyzing certified reference material and applied successfully to the analysis of environmental water samples.

On-line solid phase extraction system using 1,10-phenanthroline immobilized on surfactant coated alumina for the flame atomic absorption spectrometric determination of copper and cadmium

An on-line solid phase extraction (SPE) preconcentration system coupled to flame atomic absorption spectrometer (FAAS) was developed for determination of copper and cadmium at μg L −1 level. The method is based on the on-line retention of copper and cadmium on a microcolumn of alumina modified with sodium dodecyl sulfate (SDS) and 1,10-phenanthroline and subsequent elution with ethanol and determination by FAAS. The effect of chemical and flow variables that could affect the performance of the system was investigated. The relative standard deviation ( n = 6) at 20 μg L −1 level for copper and cadmium were 1.4 and 2.2% and the corresponding limits of detection (based on 3σ) were 0.04 and 0.14 μg L −1, respectively. The method was successfully applied to determination of copper and cadmium in human hair and water samples.

A preconcentration system for determination of copper and nickel in water and food samples employing flame atomic absorption spectrometry

A separation/preconcentration procedure using solid phase extraction has been proposed for the flame atomic absorption spectrometric determination of copper and nickel at trace level in food samples. The solid phase is Dowex Optipore SD-2 resin contained on a minicolumn, where analyte ions are sorbed as 5-methyl-4-(2-thiazolylazo) resorcinol chelates. After elution using 1 mol L −1 nitric acid solution, the analytes are determinate employing flame atomic absorption spectrometry. The optimization step was performed using a full two-level factorial design and the variables studied were: pH, reagent concentration (RC) and amount of resin on the column (AR). Under the experimental conditions established in the optimization step, the procedure allows the determination of copper and nickel with limit of detection of 1.03 and 1.90 μg L −1, respectively and precision of 7 and 8%, for concentrations of copper and nickel of 200 μg L −1. The effect of matrix ions was also evaluated. The accuracy was confirmed by analyzing of the followings certified reference materials: NIST SRM 1515 Apple leaves and GBW 07603 Aquatic and Terrestrial Biological Products. The developed method was successfully applied for the determination of copper and nickel in real samples including human hair, chicken meat, black tea and canned fish.

Solid-phase extraction of copper, iron and zinc ions on Bacillus thuringiensis israelensis loaded on Dowex optipore V-493

Bacillus thuringiensis israelensis loaded on Dowex optipore V-493 as new adsorbent for the separation–preconcentration of heavy metal ions has been proposed. The analytical conditions for the quantitative recoveries of copper(II), iron(III) and zinc(II) including pH, amounts of adsorbent, sample volume, etc. were investigated. The influences of alkaline and earth alkaline ions were also reported. The recovery values for the analytes are generally higher than 95%. The preconcentration factor was 37. The limit of detections of the analyte ions ( k = 3, N = 21) were 1.14 μg L −1 for copper, 2.01 μg L −1 for iron and 0.14 μg L −1 for zinc. The relative standard deviations of the determinations were found to be lower than 9%. The procedure was validated by analyzing copper, iron and zinc contents in two certified reference materials, NRCC-SLRS-4 Riverine water and NIST SRM 1515 Apple leaves. Agreements between the obtained results and the certified values were achieved. The developed preconcentration method was applied in the flame atomic absorption spectrometric determination of copper, iron and zinc in several samples including a multivitamin–multimineral tablet, dialysis solutions, natural waters and some food samples.

Flow injection determination of copper and iron in seafoods by a continuous ultrasound-assisted extraction system coupled to FAAS

Copper and iron were extracted on-line from solid seafood samples by a robust, fast and simple continuous ultrasound-assisted extraction system (CUES). CUES is connected to a flow-injection manifold, which allows on-line flame atomic absorption spectrometric determination of copper and iron. Experimental designs were used to optimize the continuous leaching procedures. These methods allowed a total sampling frequency of 46 and 18 samples per hour, with relative standard deviations of 1.6% and 0.3%, for copper and iron, respectively (for a sample containing 13.6 µg/g of copper and 217.3 µg/g of iron (dry mass)). The limits of detection for 30 mg of sample were 0.3 µg/g for copper and 0.6 µg/g for iron (dry mass). Analytical procedures were verified by the analysis of a standard reference material (lobster hepatopancreas marine, TORT-1) and were applied to several real seafood samples from the estuaries of Galicia (Spain) with satisfactory results.

Flow injection determination of copper in mussels by flame atomic absorption spectrometry after on-line continuous ultrasound-assisted extraction

Copper was extracted on-line from solid mussel samples by a simple and rapid continuous ultrasound-assisted extraction system (CUES). The CUES is connected to a flow injection manifold, which permits the on-line flame atomic absorption spectrometric determination of copper. The manifold is simple and the copper signal was obtained for a volume of 250 μl of acid leachate injected into an ultrapure water carrier stream. An experimental design was used for the optimization of the continuous leaching procedure. Compared to off-line ultrasonic-assisted extraction methods, sonication time is reduced by factors of 6–12, the leaching takes place at room temperature (20 °C), and the analysis time is reduced because centrifugation was not necessary to separate the liquid phase. The method allowed a total sampling frequency of 11 samples h −1, with a relative standard deviation for the complete procedure of 2.7% (for a sample containing 2.0 μg g −1 copper (wet mass, n=11). The limit of detection was 0.06 μg g −1 (wet mass) for 30 mg of sample. The analytical procedure was verified for a reference standard material (TORT-1). The analytical procedure was applied to mussel samples from Galicia (Spain).

On-line solid phase extraction system using PTFE packed column for the flame atomic absorption spectrometric determination of copper in water samples

A new flow injection on-line adsorption preconcentration system adapted to flame atomic absorption spectrometry (FAAS) for copper determination at the μg l −1 level was developed. Polytetrafluoroethylene (PTFE) turnings packed in a mini-column were used as sorbent material. The copper ammonium pyrrolidine dithiocarbamate (APDC) complex was sorbed on the PTFE turnings, from which it could be eluted on-line instantly by isobutyl methyl ketone (IBMK) into the flame at a flow rate of 2.3 ml min −1. The system was optimized and offered good performance characteristics with practically unlimited life time, greater flow rates and improved flexibility, as compared with other sorbent materials and the knotted reactor preconcentration systems. With 1 min preconcentration time, and a sample frequency of 40 h −1, the enhancement factor was 340, which could be further improved by increasing the preconcentration time. The detection limit was c L=0.05 μg l −1, and the precision was 1.5%, at the 2.0 μg l −1 Cu level. The method has been applied successfully to the analysis of potable, river and seawater, and its accuracy was tested by the analysis of certified reference materials and by recovery measurements on spiked samples. No significant interferences exist from other substances usually occurring in natural water.

Determination of copper, cobalt, nickel, and manganese in baby food slurries using electrothermal atomic absorption spectrometry.

The analytical conditions for the electrothermal atomic absorption spectrometric determination of copper, manganese, nickel, and cobalt in different types of baby foods using slurried samples are presented. Suspensions were prepared in a medium containing 0.1% w/v Triton X-100, 30% v/v concentrated hydrogen peroxide, 1% v/v concentrated nitric acid, 1% w/v ammonium dihydrogenphosphate (only for copper atomization), and one drop of silicon antifoam. The slurries were homogenized by using a potter and were introduced directly into the furnace. The amount of analyte extracted to the liquid phase was investigated. The graphite furnace conditions were optimized for each element. No matrix effect was observed, and calibration could be carried out using aqueous standard solutions. The detection limits were 3.4, 2.1, 5.4, and 3.7 pg for copper, manganese, nickel, and cobalt, respectively. The reliability of the procedures was checked by statistically comparing the results obtained with those found by using a previous microwave-oven mineralization stage and by analyzing several certified reference materials.

Electrothermal atomic absorption spectrometric determination of copper in nickel-base alloys with various chemical modifiers

The analytical characteristics of copper in nickel-base alloys have been investigated with electrothermal atomic absorption spectrometry. Deuterium background correction was employed. The effects of various chemical modifiers on the analysis of copper were investigated. Organic modifiers which included 2-(5-bromo-2-pyridylazo)-5-(diethylamino-phenol) (Br-PADAP), ammonium citrate, 1-(2-pyridylazo)-naphthol, 4-(2-pyridylazo)resorcinol, ethylenediaminetetraacetic acid and Triton X-100 were studied. Inorganic modifiers palladium nitrate, magnesium nitrate, aluminum chloride, ammonium dihydrogen phosphate, hydrogen peroxide and potassium nitrate were also applied in this work. In addition, zirconium hydroxide and ammonium hydroxide precipitation methods have also been studied. Interference effects were effectively reduced with Br-PADAP modifier. Aqueous standards were used to construct the calibration curves. The detection limit was 1.9 pg. Standard reference materials of nickel-base alloys were used to evaluate the accuracy of the proposed method. The copper contents determined with the proposed method agreed closely with the certified values of the reference materials. The recoveries were within the range 90–100% with relative standard deviation of less than 10%. Good precision was obtained.

Flame atomic absorption spectrometric determination of copper, zinc, calcium, magnesium and iron in fresh eggs using microvolume injection

The flame atomic absorption spectrometric determination of copper, zinc, calcium, magnesium and iron in fresh eggs using a microvolume injection technique is described. The capillary tube and glass impact bead were removed from the nebulizer and a polypropylene tube was installed in the inlet of the capillary tube of the nebulizer as the interface for microvolume injection. The injection volume was 10 μl and calibration was carried out using aqueous standards. Beer's law was obeyed in the concentration ranges of 0.1–1.5, 0.1–3.0, 0.2–4.0, 0.5–4.0 and 1.0–6.0 mg 1 −1 for Cu, Zn, Ca, Mg and Fe, respectively, and the detection limits were 0.016, 0.016, 0.035, 0.010 and 0.10 mg 1 −1, respectively. The reliability of the measurements was confirmed by analyzing a certified reference material, GBW 08551 Pork Liver. The precision was 2.6, 2.9, 3.0, 1.3 and 2.5% for Cu, Zn, Ca, Mg and Fe, respectively. The recovery with the standard additions method was good, ranging from 96.2 to 100.0%.

Atomic absorption spectrometric determination of copper and lead in silicon nitride and silicon carbide by direct atomization

A method involving atomic absorption spectrometry (AAS) with direct atomization has been developed for the determination of trace amounts of Cu and Pb in Si3N4 and SiC using a graphite furnace. The samples were ground to a particle size of less than 20 µm and mixed with 2.5 times the amount of graphite powder in a corundum mortar. A 0.5–3 mg amount of the mixed sample was weighed in a tared graphite cup and atomized in a cup-type graphite furnace. The absorbance was determined by integration of the spectral lines in the absorbance versus time spectrum. Calibration was effected using aqueous standard solutions. The absorbance versus time spectrum of Cu shows double peaks. On the basis of the X-ray diffraction patterns and scanning electron micrographs of the Si3N4–graphite powder mixture heated at the temperature of each atomization step, the first peak could be assigned to the Cu vaporizing from Si, and the second peak to the Cu vaporizing from SiC. The results for 12 α-Si3N4, two β-Si3N4 and two SiC samples were in good agreement with the values obtained by electrothermal AAS for liquid samples. The relative standard deviations for Cu (0.11–53.7 ppm m/m) and Pb (0.36–1.55 ppm m/m) are 1.6–39%(n= 5) and 4.3–17%(n= 5), respectively. The determination limits, corresponding to twice the standard deviation of the blank measurements, are 92 pg for Cu and 53 pg for Pb.

Copper, zinc, manganese, iron, lead, cadmium, mercury and arsenic in fish from Lake Tanganyika, Burundi

Atomic absorption spectrometric determination of copper, zinc, manganese, iron, lead, cadmium, mercury and arsenic in two fish species from Lake Tanganyika, Burundi, provide values that are lower than most literature data, especially for cadmium, arsenic and mercury. Tissue analysis of Lates stapersii reveals that liver accumulates the highest amount of most elements. The data illustrates that Lake Tanganyika is still a non-polluted area at the time of analysis.

Simultaneous Determination of Copper, Iron, Manganese and Zinc in Bovine Liver and Estuarine Sediment Using Flame Atomic Absorption Spectrometry with Background Correction

Abstract The simultaneous flame atomic absorption spectrometric determination of copper, iron, manganese, and zinc in bovine liver and estuarine sediment was investigated. Two methods, namely nitric acid and nitric acid/hydrogen peroxide were used to obtain the solid samples in a suitable aqueous-type form. For the marine sample, the nitric acid dissolution method for copper and zinc were acceptable (± 15% of certified values). For bovine liver, both methods gave acceptable results for all four metals. In general, Smith-Hieftje background correction gave better results than deuterium arc or no background correction.

Flow injection flame atomic absorption spectrometric determination of copper with preconcentration on ligand loaded amberlite XAD-2

Chelating sorbents obtained by loading a non-polar sorbent, Amberlite XAD-2, with Pyrocatechol Violet (PV), 4-(2-pyridylazo)resorcinol (PAR) or Eriochrome Blue Black R were used for a time-based preconcentration of CuII. The effect of preconcentration and elution flow-rate on the detection limit and the effectiveness of CuII sorption were examined. Pyrocatechol Violet loaded XAD-2 was employed for the determination of CuII by flow injection flame atomic absorption spectrometry in natural waters at the ppb level using a preconcentration time of 20 min. Superior dynamic properties of PV loaded sorbent in comparison with an hydroxyquinoline chelating resin is demonstrated. The effect of the presence of alkali, alkaline earth and some transition metal ions on CuII sorption was examined. Significant interference was observed for concentrations of Ca above 50 ppm. Interference from FeIII can be reduced by the addition of fluoride to the preconcentrated sample

Electrothermal atomic absorption spectrometric determination of copper and zinc in high-purity bismuth after thiocyanate extraction

Copper and zinc (0.01–1 μg g −1)in high-purity bismuth are extracted together as their thiocyanate complexes into methyl isobutyl ketone and determined by atomic absorption spectrometry with a tungsten-strip atomizer. The concentrations of copper found by the proposed method agree well with the values obtained by similar atomic absorption spectrometric methods involving prior extraction of copper as its bathocuproine or diethyldithiocarbamate complex.

Determination of metals after collection of their acenaphthene-quinone dioxime complexes on microcrystalline naphthalene

A method is described for the atomic absorption spectrometric determination of copper(II), nickel(II), cobalt(II) and palladium(II) after collection of their acenaphthenequinone dioxime complexes on microcrystalline naphthalene. The complexes collected are dissolved in dimethylformamide (DMF) for copper(II), in nitric acid-DMF for nickel(II) and cobalt(II) and in butylamine-DMF for palladium(II). These metals are determined by atomic absorption spectrometry. Beer's law is obeyed up to 80, 100, 100 and 90 µg of CuII, NiII, CoII and PdII, respectively, in 10 ml of final organic solvent. Ten replicate determinations of a sample solution containing 40 µg of CuII and 60 µg of each of NiII, CoII and PdII gave mean absorbances of 0.260, 0.160, 0.260 and 0.195, respectively, with relative standard deviations of 0.9, 1.1, 1.11 and 1.27%, respectively. The method was applied to the determination of these metal ions in some standard and practical samples.

Atomic absorption spectrometric determination of copper in calcium carbonate scale and carbonate rocks by direct atomization of solid samples

Powdered samples (1 mg) are mixed with 1 mg of powdered graphite and copper is determined by atomic absorption spectrometry in a miniature graphite cup placed in a graphite crucible. Optimum conditions were drying at 200 °C (30 s), ashing at 900 °C (30 s), atomizing at 2700 °C (15 s) and cleaning at 2800 °C (10 s). Samples were powdered to 1–10 μm particle size. Magnesium, manganese and iron did not interfere. The effect of calcium carbonate was eliminated by the graphite addition. Results for copper (0.5–5 μg g −1) in the scale and rocks agreed well with values obtained for dissolved samples. Relative standard deviations ( n=10) were 4.9% for 1.2 μg g −1 copper and 14.8% for 0.577 μg g −1.