Atomic absorption spectrometric determination of chromium, copper, lead, mercury, and zinc in sediments collected in Bayou d'Inde, southwestern Louisiana

The concentrations of the metals chromium (Cr), copper (Cu), lead (Pb), mercury (Hg), and zinc (Zn) were determined in sediment cores taken from Bayou d'Inde in southwestern Louisiana. Previous studies had reported elevated concentrations of these trace metals in sediments along this waterway. The current study, conducted more than a decade later, was designed to determine if these metals had migrated from the areas of highest concentrations. Concentrations as high as 400 mg/kg for Cr, 1100 mg/kg for Cu, 10 mg/kg for Hg, and 600 mg/kg for Pb and Zn were found. Areas of high concentrations of metals were isolated within a distance of about 1 km from the most highly contaminated areas in the bayou. Low concentrations of metals were found at the mouth of the bayou. Estimated sedimentation rates of 0.67-1.2 cm/yr were based on the burial of the sediments originally studied. The concentrations of the metals studied remained high and were also highly localized, both spatially and temporally.     

Atomic absorption spectrometric determination of phosphorus in biological materials

The phosphorus content in the National Bureau of Standards, Standard Reference Materials orchard and tomato leaves, bovine liver and oyster tissue is determined by three atomic absorption spectrometric techniques: measurements of solid and liquid samples against liquid standards, and measurements based on standard additions. All methods gave results which agreed well with the certificate values. Compared to methods involving decomposition and atomization from solution, solid sampling offers the advantages of being direct and fast, and of requiring only small amounts of sample.     

Atomic-absorption spectrometric determination of cobalt,nickel, and copper in geological materials with matrix masking and chelation-extraction

An atomic-absorption spectrometric method is reported for the determination of cobalt, nickel, and copper in a variety of geological materials including iron- and manganese-rich, and calcareous samples. The sample is decomposed with HP-HNO₃ and the residue is dissolved in hydrochloric acid. Ammonium fluoride is added to mask iron and 'aluminum. After adjustment to pH 6, cobalt, nickel, and copper are chelated with sodium diethyl-dithiocarbamate and extracted into methyl isobutyl ketone. The sample is set aside for 24 h before analysis to remove interferences from manganese. For a 0.200-g sample, the limits of determination are 5–1000 ppm for Co, Ni, and Cu. As much as 50% Fe, 25% Mn or Ca, 20% Al and 10% Na, K, or Mg in the sample either individually or in various combinations do not interfere. Results obtained on five U.S. Geological Survey rock standards are in general agreement with values reported in the literature.     

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.     

Atomic-absorption determination of lead in geological materials

A method is described for the determination by atomic-absorption spectrophotometry of lead, tip to the milligram level, in samples of geological materials. After attack with perchloric-hydrofluoric acid mixture and the removal of perchlorate ion by precipitation as potassium perchlorate, lead is separated from matrix elements by means of anion-exchange in 2M hydrobromic acid on the strongly basic anion-exchange resin Dowex 1 x 8. Lead is adsorbed on the resin column while practically all other accompanying elements pass into the effluent. For the elution of lead 6(M) hydrochloric acid is used and after evaporation of the eluate lead is determined by atomic-absorption spectrophotometry. The method was tested by analysing numerous samples with contents ranging from a few ppm to milligram amounts of lead. In most cases very good agreement of results was obtained.     

Atomic absorption spectrometric determination of trace amounts of copper and zinc after simultaneous solid-phase extraction and preconcentration onto modified natrolite zeolite.

This work assesses the use of modified natural natrolite zeolite as an adsorptive material for the separation and preconcentration of trace amounts of ions. In this work we investigated the potential of modified natural natrolite zeolite for the simultaneous separation and preconcentration of trace amounts of copper and zinc ions. We have developed a simple, rapid, selective, sensitive and economical method for the simultaneous separation and preconcentration of trace amounts of copper and zinc in an aqueous medium using 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) as an analytical reagent. The sorption was quantitative in the pH range 7.5 - 9.5, whereas quantitative desorption occurred instantaneously with 5.0 mL of 2 mol L(-1) nitric acid. Linearity was maintained between 0.05 - 6.0 microg mL(-1) for copper and 0.02 - 1.5 microg mL(-1) for zinc in the final solution. Ten replicate determinations of 1.0 microg mL(-1) copper and 0.5 microg mL(-1) zinc in a mixture gave mean absorbances of 0.1687 and 0.2788 with relative standard deviations of +/-1.2% and +/-1.3%, respectively. The detection limits were 0.03 ng mL(-1) for Cu(II) and 0.006 ng mL(-1) for Zn(II) in the original solution (3 sigma(bl)/m). Different parameters, such as the effect of the pH, flow rate, breakthrough volume and interference of a large number of anions and cations, were studied and the proposed method was used for the determination of these metal ions in water as well as standard samples (e.g. Nippon Keikinzoku Kogyo (NKK) CRM, No. 916 and No. 920 aluminum alloy, National Institute for Environment Studies (NIES) No. 1 pepperbush and NIES No. 2 pond sediment). The determination of these metal ions in standard samples showed that the proposed method has good accuracy (recovery > 97%).     

Atomic absorption spectrometric determination of indium in gallium arsenide

Summary The determination of indium in heavily doped gallium arsenide (0.2–1.2 mg g^–1 In), by both electrothermal and flame AAS is reported. The sample is first decomposed with nitric acid and the diluted solution is atomized by employing the more convenient technique. The conventional air-acetylene flame is used for samples containing at least 1 mg g^–1 indium. For lower concentrations the electrothermal atomization is required and matrix-matched standards become necessary. Platform sampling is shown to improve both sensitivity and repeatability in comparison with the tube-well sampling. Dependence of the matrix effect on both the signal measurement mode and deterioration of the platform is examined. By increasing the sample mass up to 100 mg, without further dilution of the solution to be injected into the furnace but with the optical correction of the background, a detection limit (6 s) of 4.2 ng g^–1 (1.2×10¹⁴ atoms cm^–3) is achieved. The method was applied to In doped GaAs samples and the results are compared with those independently obtained by differential pulse polarography.

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AAS-Bestimmung von Indium in Galliumarsenid

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This work was presented at the Euroanalysis VI Conference (Paris, September 7–11, 1987)     

Atomic absorption spectrometric determination of aluminium in whole blood

Two methods are described for atomic absorption spectrometric determinations of aluminium m heparinized and haemolyzed samples of undiluted whole human blood. In the direct method 2μl of blood are pipetted into a graphite cup atomizer; after a drying and two ashing steps aluminium is determined by atomization at 2500°C. In the second method, 15μl of blood are decomposed by nitric acid in polytetrafluoroethylene tubes; 2-μl portions of the solution are then analyzed with the graphite tube atomizer. The direct method was applied to the determination of aluminium in whole blood from 48 Norwegian workers occupationally unexposed to the element; the concentrations of aluminium ranged from 0.05—0.59 p.p.m. (mean value, 0.20 p.p.m.). For 0.35 p.p.m. aluminium, the relative standard deviation of both methods was 8%. The detection limit of the direct method is 0.05 p.p.m. aluminium.     

Simultaneous preconcentration of copper, nickel, cobalt and lead ions prior to their flame atomic absorption spectrometric determination

A sensitive and simple method for the simultaneous preconcentration of nutritionally important minerals in real samples has been reported. The method is based on the adsorption of Cu2+, Ni2+, Co2+ and Pb2+ on 4-propyl-2-thiouracil (PUT) loaded on activated carbon. The metals on the complexes are eluted using 5 mL 3 M HNO3 in acetone. The influences of the analytical parameters including pH and sample volume were investigated. The effects of matrix ions on the retentions of the analytes were also examined. The recoveries of analytes were generally higher than 95%. The detection limits for Cu2+, Ni2+, Co2+ and Pb2+ were 1.6, 1.3, 1.2, 2.3 ng ml(-1), respectively. The method has been successfully applied for these metals content evaluation in some real samples including natural water samples.     

Computerized potentiometric stripping analysis for the determination of cadmium,lead, copper and zinc in biological materials

Two different types of tinned mussels and a bovine liver reference sample have been analyzed for Zn, Cd, Pb and Cu by means of computerized potentiometric stripping analysis and atomic absorption spectrometry. The samples were digested by two different procedures, one employing nitric acid only and the other employing nitric and perchloric acids. It is shown that computerized stripping analysis can be used in samples containing high concentrations of electroactive organic nitro compounds, without sample deoxygenation.     

Atomic absorption spectrometric determination of manganese, silver and zinc in dental material by atomization directly from the solid state

The direct-atomization. technique of atomic absorption spectrometry was applied to the determination of manganese, silver and zinc in 14 whole erupted or unerupted human teeth. Pulverized sample-graphite mixtures of 5–10 mg, to which known volumes of metal standard solution had been added, were dried, ashed and atomized in a graphite furnace, as in the standard addition technique. The technique was also used for determining silver and zinc in an international reference sample of calcined animal bone.     

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 mul 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%.     

Electrothermal atomic absorption spectrometric determination of cobalt, copper, lead and nickel traces in aragonite following flotation and extraction separation

A method of determination of Co, Cu, Pb and Ni in nanogram quantities from aragonite is presented. Flotation and extraction of Co, Cu, Pb and Ni is suggested as methods for elimination matrix interferences of calcium. The method of flotation is performed by iron(III) hexamethylenedithiocarbamate, Fe(HMDTC)(3), as a colloid precipitate collector. The liquid-liquid extraction of Co, Cu, Pb and Ni is carried out by sodium diethyldithiocarbamate, NaDDTC, as complexing reagent into methylisobutyl ketone, MIBK. The electrothermal atomic absorption spectrometry (ETAAS) is used for determination of analytes. The detection limits of ETAAS followed by flotation are: 7.8 ng.g(-1) for Co, 17.1 ng.g(-1) for Cu, 7.2 ng.g(-1) for Pb and 9.0 mug.g(-1) for Ni. The detection limits of ETAAS followed by extraction are found to be: 12.0 ng.g(-1) for Co, 51.0 ng.g(-1) for Cu, 24.0 ng.g(-1) for Pb and 21.0 ng.g(-1) for Ni.     

Atomic absorption spectrometric determination of cadmium and lead in dental material by atomization directly from the solid state

The direct-atomization technique of atomic absorption spectrometry was applied to the determination of cadmium and lead in 14 whole erupted or unerupted human teeth. Pulverized samples of 0.5–3 mg were dried, ashed and atomized in a graphite furnace; hydroxyapatite was used as the solid standard. The method is simple, rapid and sensitive, and no reagents are added to the samples.     

Enzymatic determination of cadmium,zinc, and lead in plant materials

Prospects are outlined for using the following enzymes (native and immobilized on polyurethane foam) in the rapid and highly sensitive determination of cadmium, zinc, and lead ions in plant materials (wild grass, fresh pea, and grape): horseradish peroxidase and alkaline phosphatases isolated from chicken intestine and Greenland seal small intestine. The analytical ranges of the above metals are 1 × 10^–3?25, 7 × 10^?3?250, and 3 × 10^?2?67 mg/kg dry matter, respectively. The enzymatic determination procedures developed are based on the inhibiting effect of metal ions on the catalytic activity of peroxidase in the oxidation of o-dianisidine with hydrogen peroxide and alkaline phosphatases in the hydrolysis of p-nitrophenyl phosphate. The rates of enzymatic reactions were monitored spectrophotometrically or visually. In the analysis of plant extracts, their high acidity was diminished by choosing optimum dilution factors and pH values for test samples and the nature and concentration of a buffer solution. The interference of iron(III) was removed by introducing a 0.1 M tartaric acid solution into the indicator reaction. The accuracy of the results of the enzymatic determination of cadmium, zinc, and lead in plant materials was supported by atomic absorption spectrometry and anodic stripping voltammetry.     

Electrothermal atomic absorption spectrometric determination of trace lead,copper and manganese in aluminum and its alloys without preliminary separation

Graphite-furnace atomic absorption spectrometry is used for the determination of >0.001% of lead, copper and manganese in aluminum and its alloys. The samples are dissolved in hydrochloric acid and analyzed directly after addition of a slight excess of (NH₄)₂ EDTA over aluminum. Sample and standard solutions must contain equal amounts of EDTA.     

Atomic absorption spectrometric determination of selenium with carbon furnace atomization

A Varian Techtron model 63 carbon rod atomizer is used for the atomic absorption spectrometric determination of nanogram quantities of selenium. The pronounced interferences from the matrices in biological digests can be obviated by isolating selenium from sample matrices by precipitation with ascorbic acid. The precision of the determination is improved by incorporating 5000 μg Ni ml^?1 in the analytical solutions. Selenium at μg g^?1 and sub-μg g^?1 levels in a variety of biological samples can be determined. The detection limit is 25 ng Se g^?1.     

Direct atomic absorption spectrometric determination of cadmium,lead and manganese in bone and of lead in ivory

Various atomic absorption spectrometric methods — including the solid sampling technique — are described for the determination of cadmium, manganese and lead in hard tissue. The methods were used in the analysis of hydroxyapatite, ivory and animal bone.