Carbon Tube Atomizer Research Articles

Packed glassy carbon tube atomizer for direct determinations by atomic absorption spectrometry, free from background absorption

An electrothermal atomizer consisting of a long glassy carbon tube packed with activated charcoal was evaluated for the direct determination of trace elements in biological materials by atomic absorption spectrometry, in the absence of any background absorption. The maximum temperature of the atomizer of 2280 °C was maintained continuously by an electric power supply of about 7 kW. Under such isothermal conditions, few chemical interferences and high accuracy (relative error <8%) and precision (RSO <3.5%) were obtained in the direct determination of trace elements (Cu, Mg and Mn) in National Institute of Standards and Technology biological Standard Reference Materials by solid sampling atomic absorption spectrometry.

Determination of Trace Amount of Bismuth in Some Sediments by Graphite Furnace Atomic Absorption Spectrometry after Preconcentration as Xanthogenate Complex on Activated Carbon

This method is based on the direct heating of activated carbon (AC) adsorbed bismuth-potassiumo-ethyldithio-carbamate [potassium xanthogenate (KetX)] complex: that is, AC is introduced directly as into a carbon tube atomizer, without the desorption of bismuth from the AC. To a sample solution (pH 6.5-8.0) containing less than 0.10μg of bismuth, potassium tartrate as a masking agent, 120mg of KetX and 50mg of AC are added, and the mixture is stirred for 20s. After separation of AC from the aqueous phase through a membrane filter, 5.0ml of AC-suspension are prepared by adding water to the AC. Then, aliquots (10μl) of AC-suspension are injected into the atomizer, and the bismuth peak-height is measured under optimal instrumental operating conditions. The determination limit was 0.005μg/100ml (S/N=3), and the relative standard deviation was 2.0% (n=8). This method was applied to the determination of bismuth in river-bottom and submarine sediments.

Cation Exchange Studies of Cadmium Chloride, Bromide and lodide Complexes in Aqueous Acetone Solution

The distribution equilibria between cadmium (II) chloride, bromide, iodide and perchlorate complexes and the cation exchange resin in aqueous acetone solutions have been investigated. Formation constants of cadmium halides or perchlorate have been calculated from the distribution coefficients of cadmium in aqueous acetone solutions containing 10, 20, 30 and 40 v/v% water. Cadmium concentrations of the solutions have been measured by the atomic absorption spectrophotomer equipped with a carbon tube atomizer. The logarithmic values of constants in 10 v/v% aqueous acetone are: β1Cl =6.25, β2Cl =11.05 and β3Cl =14.59 for cadmium chloride, β1Br=6.97 and β2Br=10.35 for cadmium bromide, β1I=7.02 and β2I=11.80 for cadmium iodide, β1ClO4=2.18 for cadmium perchlorate. Formation constants of cadmium chloride are lower than those of cadmium iodide because of soft basicity of cadmium.

Determination of Bismuth in Eighty‐Three Geochemical Reference Samples by Atomic Absorption Spectrometry

The bismuth content of eighty‐three geochemical reference samples has been determined by atomic absorption spectrometry using either a hydride generation and heated quartz cell atomizer or a solvent extraction and carbon tube atomizer. The agreement between the present results and published data is generally good.

Determination of Selenium in Twenty‐Eight Geological Reference Materials by Atomic Absorption Spectrometry

Twenty‐eight geological reference samples have been analysed for selenium using atomic absorption spectrometry with hydride generation and quartz cell atomizer and/or with solvent extraction and carbon tube atomizer. Data are presented for 5 CCRMP, 6 USGS, 3 NBS, 6 NIM and 8 GSJ reference materials.

Determination of Cadmium and Lead in Seventy‐seven Geological Reference Samples by Atomic Absorption Spectrometry

The cadmium and lead contents of seventy‐seven geological reference samples have been determined by atomic absorption spectrometry using an air‐acetylene flame or a carbon tube atomizer, after extraction of cadmium and lead as iodides with methylisobutylketone (MIBK). The agreement between the present results and published data is generally good.

Determination of Beryllium in Eighty Geological Reference Samples by Atomic Absorption Spectrometry

The beryllium content of eighty geological reference samples has been determined by atomic absorption spectrometry using a nitrous oxide‐acetylene flame or a carbon tube atomizer, after extraction of beryllium as acetylacetonate with methylisobutylketone (MIBK). The agreement between the present results and published data is generally good.

Electrothermal atomic absorption spectrometry for aluminum by direct heating of aluminum-adsorbed chelating resin.

A sensitive method for the determination of ppb levels of aluminum by electrothermal atomic absorption spectrometry has been established. This method is based on the direct heating of aluminum-adsorbed resin; that is, the resin is introduced directly as a into a carbon tube atomizer, without weighing the resin or eluting the aluminum from the resin. To a 250 cm3 sample solution ( pH: 4.0 ) containing less than 1.0 μg of aluminum, 0.10 g of chelating resin ( NH4-form, below 400 mesh ) is added, and the mixture is stirred for 10 min. Following separation of the resin from the aqueous phase through a membrane filter, 5.0 cm3 of resin-suspension are prepared by adding water to the resin. Then, 10 μdm3 ( resin: 0.2 mg ) of the suspension are injected into the atomizer, and the aluminum peak-area is measured under optimum instrumental operating condition. The calibration graph was linear up to 4.0 ppb of aluminum, and the relative standard deviation was 4.1 % at 2.0 ppb level of aluminum. This method was applied to the determination of aluminum in water samples.

Atomic absorption spectrometry of dysprosium by a pyrolytic-graphite-coated carbon tube atomizer

Atomic absorption spectrometry of dysprosium by a pyrolytic-graphite-coated carbon tube atomizer

A Sensitive Atomic Absorption Spectrometric Method for Copper Employing the Direct Introduction of Chelating Resin into a Carbon Tube Atomizer

Abstract A new and simple method for the determination of ppb levels of copper by electrothermal atomic absorption spectrometry was established. The main feature of the proposed method is that chelating resin, a preconcentration agent for copper, is introduced directly as a “resin-suspension” into the carbon tube atomizer without drying and weighing of the resin. To a 250 cm3 sample solution containing up to 1.0 μg of copper, 0.10 g of chelating resin (below 400 mesh) is added, and the mixture is stirred for about 20 min. After the separation of the resin from the aqueous phase through a membrane filter, 5.0 cm3 of resin-suspension is prepared by adding water to the resin. Then, 10 μdm3 (resin: 0.2 mg) of the suspension is introduced into an atomizer, and the copper peak-height is measured under the optimum operating conditions. The calibration graph was linear over the concentration range from 0.1 ppb to 4.0 ppb of copper. The relative standard deviation was 2.3% from 10 repeated measurements; a mean value of 1.08 ppb copper was obtained for a sea water sample.

Differential determination of tellurium(IV) and tellurium(VI) with sodium diethyldithiocarbamate, ammonium pyrrolidinedithiocarbamate and dithizone by atomic-absorption spectrophotometry with a carbon-tube atomizer

The extraction behaviour of tellurium(IV) and tellurium(VI) with sodium diethyldithiocarbamate, ammonium pyrrolidinedithiocarbamate and dithizone in organic solvents has been investigated by means of flameless atomic-absorption spectrophotometry with a carbon-tube atomizer. The selective extraction of tellurium(IV) and differential determination of tellurium(IV) and tellurium(VI) have been developed. With sodium diethyldithiocarbamate and carbon tetrachloride, when the aqueous phase/organic solvent volume-ratio is 5 and the injection volume in the carbon tube is 20 μl, the sensitivity for tellurium is 0.3 ng/ml for 1% absorption. The relative standard deviations are ca. 2%. The proposed methods have been applied satisfactorily to determination of tellurium(IV) and tellurium(VI) in various types of water.

Determination of cobalt in biological samples by trioctylamine extraction-atomic absorption spectrometry using a carbon tube atomizer

Determination of cobalt in biological samples by trioctylamine extraction-atomic absorption spectrometry using a carbon tube atomizer

原子吸光分析における光干渉 Ｖ ストロンチウムおよびバリウム塩の分子吸収スペクトル

Spectral interferences were observed in trace element analysis of concentrated solutions by atomic absorption spectrometry. Molecular absorption and emission spectra for strontium chloride and nitrate, barium chloride and nitrate containing 12 mg/ml of metal ion in airacetylene flame were measured in the wavelength range from 200 to 700 nm. The absorption and emission spectra of SrO were centred near 364.6 nm. The absorption spectra of SrOH around 606. 0, 671. 0 and 682.0 nm were very strong. And, emission spectrum of BaOH in the wavelength range from 480 to 550 nm was stronger. But, the absorption of this band spectrum was very weak. In the wavelength range from 200 to 400 nm, some unknown bands of absorption were observed for strontium and barium. Absorption spectra of SrCl and BaCl were observed in the argon-hydrogen flame. Also, in the carbon tube atomizer, the absorption spectra of SrCl and BaCl were detected clearly in the wavelength range from 185 to 400 nm.

Simple method for determination of selenium in biological materials by flameless atomic-absorption spectrometry using a carbon-tube atomizer

A method for determination of selenium in biological materials by flameless atomic-absorption spectrometry using a carbon-tube atomizer is described. The sample is burned by an oxygen-flask combustion procedure, the resulting solution is treated with a cation-exchange resin to eliminate interfering cations, the selenium is extracted with dithizone in carbon tetrachloride and the resulting selenium dithizonate is combined with nickel nitrate in the carbon tube to enhance the sensitivity for selenium and avoid volatilization losses. The method measures selenium concentrations as low as 0.01 μg/g with a relative standard deviation of 8%.

原子吸光分析における光干渉 Ｉ リチウム塩の分子吸収スペクトル

Molecular absorption spectra produced by some lithium salts such as lithium chloride, hydroxide and nitrate in the carbon tube atomizer, air-acetylene flame and argon-hydrogen flame were determined in the wavelength range 1900 to 4000 Å.In the air-acetylene and argon-hydrogen flames, the absorption spectra for LiCl were obtained in the 2000-2450 Å region, and the spectra for LiOH were obtained in the 2000-3300 Å region. In the fuel rich hydrogen-air-argon flame, the density of atomic lithium vapor increased.LiCl and NO molecular absorption spectra were obtained in the carbon tube atomizer. An absorption spectrum for NO was observed at about 600°C, the dissociation temperature of lithium nitrate. The absorption spectrum for LiCl was observed at 1350°C, the boiling point of lithium chloride.The absorption spectrum for LiOH was undetectable by lithium hydroxide solution in the carbon tube atomizer.

Differential determination of selenium(IV) and selenium(VI) with sodium diethyldithiocarbamate, ammonium pyrrolidinedithiocarbamate and dithizone by atomic-absorption spectrophotometry with a carbon-tube atomizer

The extraction behaviour of selenium(IV) and selenium(VI) with sodium diethyldithiocarbamate, ammonium pyrrolidinedithiocarbamate and dithizone in organic solvents has been investigated by means of flameless atomic-absorption spectrophotometry with a carbon-tube atomizer. The selective extraction of selenium(IV) and differential determination of selenium(IV) and selenium(VI) have been developed. With sodium diethyldithiocarbamate and carbon tetrachloride, when the aqueous phase/organic solvent volume ratio is 5 and the injection volume in the carbon tube is 20 μl, the sensitivity for selenium is 0.4 ng/ml for 1% absorption. The relative standard deviations are ca. 3%. Interference by many metal ions can he prevented by masking with EDTA. The proposed methods have been applied satisfactorily to determination of Se(IV) and Se(VI) in various types of water.

Spectral Interferences in Atomic Absorption Spectrometry (II)

Molecular absorption spectra produced by some potassium salts in air-acetylene and air-argon-hydrogen flames were observed in the wavelength range 1900 to 4000 Å.The absorption spectrum of KCl was obtained by potassium chloride in 1900-3000 Å region. The absorption spectra of KOH produced by potassium hydroxide and nitrate in the flame were detected in 2000-4000 Å region.In the carbon tube atomizer, an absorption spectrum of KC1 was determined in 1900-3700 Å region by potassium salts including chlorine such as potassium chloride and perchlorate.The spectrum of NO was observed by potassium nitrate, but for KOH was undetectable in the carbon tube atomizer.Absorption spectra of K2S were measured by potassium sulfide, sulfate and bisulfate in 1850-4000 Å. And SO2 absorption spectra were detected by sulfuric acid and potassium bisulfate.An absorption spectrum for potassium phosphate was detected in the UV region.

Determination of cadmium in sediments by atomic absorption spectrophotometry with a carbon tube atomizer

Determination of cadmium in sediments by atomic absorption spectrophotometry with a carbon tube atomizer

Selective determination of antimony(III) and antimony(V) with ammonium pyrrolidinedithiocarbamate, sodium diethyldithiocarbamate and dithizone by atomic-absorption spectrometry with a carbon-tube atomizer

The extraction behaviour of antimony(III) and antimony(V) with ammonium pyrrolidinedithiocarbamate, sodium diethyldithiocarbamate and dithizone in organic solvents has been investigated by means of frameless atomic-absorption spectrophotometry with a carbon-tube atomizer. The selective extraction of antimony(III) and differential determination of antimony(III) and antimony(V) have been developed. With ammonium pyrrolidinedithiocarbamate and methyl isobutyl ketone, when the aqueous phase/solvent volume ratio is 50 ml/10 ml and the injection volume in the carbon tube is 20 μl, the sensitivity for antimony is 0.2 ng/ml for 1% absorption. The relative standard deviations are ca. 2%. Interferences by many metal ions can be prevented by masking with EDTA. The proposed methods have been applied satisfactorily to determination of antimony(III) and antimony(V) in various types of water.

Vaporization of atoms and molecules during heating of cadmium, lead and zinc salts in a carbon tube atomizer

Vaporization characteristics of atoms and molecules produced during heating of aqueous solutions of Cd, Pb and Zn salts in the carbon tube atomizer are described. Sulfates, nitrates and fluorides are decomposed completely to free atoms without losses. When concentrated halide solutions are employed, gaseous metal chlorides, bromides and iodides are removed partly from the atomizer in the initial atomization phase, and the atomic absorption response is decreased. This loss can be suppressed effectively by adding nitric or sulfuric acid to the halide solutions.