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At least 775 records · Page 43Linked to original sources
PubMed1997

[Characteristic mass and atomization efficiency of graphite furnace atomic absorption spectrometry].

Measurements of peak height and peak area characteristic masses and atomization efficiency for 7 elements (Ag, Bi, Cd, Cr, Ga, Ge and In) have been studied. The m0(i)(exp) values are compared with theoretical data, m0(i)(cal), to assess the effect of temperature on the correction factor of theorization for characteristic mass value (alpha = m0(i)(cal) m0(i)(exp)), the peak height and the peak area atomization efficiencies (betap and betai). The peak area atomization efficiency (betai) was equal to the correction factor of theorization for characteristic mass value (alpha) times tauD/tauR value. The tauR was value experimentally measured of atomic residence time and the tauD value calculated from rD = l2/8D. The betai value of elements always are smaller than the alpha values because the tauD/tauR values is less than one for most elements in the operating conditions. Past of the analyte vapours is readsorbed by the heated tube wall at high temperature and reevaporation of the adsorbed analyte followed by diffusion account for the larger atomic residence time and it appeared that the tauR value was larger than the tauD in graphite furnace.

English Abstract↗
PubMed1998

[Determination of beryllium in geological samples with slurry sampling and probe atomization in graphite furnace atomic absorption spectrometry].

A method of loading a slurry prepared from a solid sample for analysis of beryllium in geological samples using graphite furnace atomic absorption spectrometry was approached by combining slurry sampling with probe atomization. The factors that influence the performances of beryllium including ashing and atomization temperature, atomization surfaces (probe and tube), the materials of the tube and probe, and the use of matrix modifiers were investigated. The results show that the determination of beryllium in geological samples could be performed by direct slurry sampling with the use of calcium as the matrix modifier for a calibration established with aqueous standards. The relative standard deviations (RSD) of the method were 3.1-5.2%. The analytical results of the geological reference samples were consistent with the certified values. The activation energy during beryllium atomization was calculated using the Arrhenius graph method which was in good with the bonding energy of Be-O.

English Abstract↗
PubMed1997

[Recent advances in absolute analysis by graphite furnace atomic absorption spectrometry].

This paper summarizes recent advances in absolute analysis by graphite furnace atomic absorption spectrometry, including the developments of absolute analysis in atomic absorption spectrometry, the theoretical calculation of characteristic mass, the study of the stability of experimental characteristic mass and the applications of standardless analysis in various samples.

English Abstract↗
PubMed1999

[A Zeeman graphite furnace atomic absorption spectrometric method for the determination of trace copper and chromium in drinking water].

The determination of trace copper and chromium in drinking water is described in this paper using transverse heated graphite atomizer (THGA) with the technique of Zeeman effect background correction without any other matrix modifiers. The method is fast, and simple with low detection limit which makes it possible to be used for routine analysis of drinking water.

Chromium↗
PubMed1999

[Determination of inorganic and organic tin in water samples by graphite furnace atomic absorption spectrometry].

This paper proposed a method for the determination of inorganic tin and organotin species. Total tin contents can be directly detected by zirconium-coated graphite furnace atomic absorption spectrometry,while the organotin was detected by hydride generation combined with solvent extraction and the difference between the total tin and organotin was inorganic tin. The detection limits were 58 pg and 27 pg for organotin and inorganic tin,respectively. The relative standard deviations of this procedure, were 2.13% and 2.04%, respectively. Several water samples were analyzed by this method. The recoveries ranging from 90.5% and 98.5% were obtained.

Spectrophotometry, Atomic↗
PubMed2006

[Determination of trace selenium in edible fungi with graphite furnace atomic absorption spectroscopy].

In the present article, samples were digested by a quartz high-pressure digestion pot, reducing the loss of selenium in digestion. The content of selenium in edible fungi was determined by using graphite furnace atomic absorption spectroscopy, and the results showed that when the content of selenium in edible fungi was determined by using 1% Ni(NO3)2 as a matrix modifier, ashing temperature of 500 degreed C, and atomization temperature of 2 500 degrees C, and rectifying background by deuterium light, the recovery was in the range of 92.1%-115.5%, the relative standard deviation of the method was 1.28%, and the limit of detection was 15.8 microg x L(-1). The method was suitable for the determination of trace selenium in edible fungi with the advantages of being simple, rapid, sensitive, stable and accurate etc., and the results were satisfactory.

Agaricales↗
PubMed2006

[Direct determination of lead and cadmium in soil by slurry-sampling graphite furnace atomic absorption spectrometry using matrix modification technique].

A method for the direct determination of lead and cadmium in soil by slurry-sampling graphite furnace-atomic absorption spectrometry using NH4 H2 PO4 as matrix modifier was developed. The effects of slurry stability, particle size of sample, matrix modifiers, ashing temperature, atomization temperature and common coexistent components on the signal intensities of lead and cadmium were investigated. The apparent activation energies of lead and cadmium were measured based on the linear relationship between the logarithm value of atomization peak time and atomization temperature. The mechanism of matrix modification was discussed. Under optimized conditions, the detection limit was 9.05 x 10(-10) g x mL(-1) for Pb and 1.76 x 10(-11) g x mL(-1) for Cd. The recoveries were in the range of 91%-97% for Pb and 93%-109% for Cd. The relative standard deviations were in the range of 4.2%-7.8%.

Cadmium↗
PubMed2006

[Determination of As, Pb, Sn, Sb and Bi in high temperature iron and nickel-based alloy by graphite furnace atomic absorption spectrometry combined with liquid-liquid extraction].

A method was developed for the determination of As, Pb, Sn, Sb and Bi in high temperature iron and nickel-based alloy by graphite furnace atomic absorption spectrometry combined with liquid-liquid extraction. These elements formed complexes with I- ions and were subsequently extracted into MIBK to be separated from matrix elements. The effects of remnant matrix elements were studied in detail. Meanwhile, the interferences of other elements, such as W, Nb and Ta, were eliminated with masking method. The recovery rates for As, Pb, Sn, Sb and Bi are in the range of 93%-99%, and the relative standard deviations are from 8.8% to 12%.

English Abstract↗
PubMed2006

[Slurry sampling for direct determination of trace cadmium in amber by graphite furnace atomic absorption spectrometry].

A method for the direct determination of trace cadmium in amber by graphite furnace atomic absorption spectrometry (GFAAS) with slurry sampling was described. Palladium nitrate was used as a matrix modifier to eliminate the interference. Slurry stability and the influences of the matrix modifier, ashing/atomization temperature and coexistent ions on analytical signals were investigated in detail. Under the optimized experimental conditions, the detection limit of this method was 9.4 ng x g(-1) with a precision of 6.1%.

English Abstract↗
PubMed1991

Determination of dietary cadmium-induced metallothioneins in rabbit kidneys and cadmium in metallothioneins by anion-exchange high-performance liquid chromatography coupled with graphite furnace atomic absorption spectrometry.

A rapid method is described for the determination of dietary cadmium-induced metallothioneins (MTs) in rabbit kidneys by anion-exchange high-performance liquid chromatography. Rabbit kidney MT-I and MT-II were eluted at ca. 15.0 and 18.8 min, respectively, from a DEAE-5PW anion-exchange column with a Tris-HCl buffer (0.01-0.25 M, pH 8.6) and detected by ultraviolet absorbance at 254 nm. A standard calibration curve was constructed using purified standard MT isoforms, which demonstrated an excellent linear correlation between UV absorbance peak heights and the amounts of MT isoforms. Feeding a dose of cadmium for some days resulted in an increase in MT concentrations in rabbit kidneys, but not in the livers. The cadmium concentrations in MT-I and MT-II elutions were determined by graphite furnace atomic absorption spectrometry. MT-I and MT-II showed some differences associated with the oral intake of cadmium. Dietary cadmium also caused zinc to accumulate in kidneys to some extent. The effects of dietary oleic acid on the synthesis of MTs were also studied. Based on the method of standard additions, the recovery of MTs exceeded 93% and replicated injection of samples yielded a relative standard deviation of 2.4% at an MT level of 280 micrograms/g.

Animals↗
PubMed1991

Determination of Cd, Cr, Cu, Pb and Zn in human semen by graphite furnace atomic absorption spectrometry after microwave sample dissolution.

Human semen samples were analyzed by graphite furnace atomic absorption spectrometry, using L'vov platforms and the method of standard additions, to determine their Cd, Cr, Cu, Pb and Zn content. The samples were analyzed directly and after conventional and microwave wet acid dissolution. Matrix modification, using magnesium and palladium nitrates and ammonium biphosphate solutions, was evaluated for the analysis of the microwave-digested samples. The best results were obtained for Cr, Cu and Zn using Pd(NO3)2, and a mixture of Mg(NO3)2 and Pd(NO3)2 solutions. The direct analysis of water-diluted semen produced inaccurate results with unacceptably high standard deviations. The results obtained for the microwave-dissolved samples showed relative standard deviation values within the range 0.63-8.4%. The analysis of spiked semen solutions showed recoveries of the added analytes ranging from 96 to 104%. The accuracy of the measurements was checked against the NIST 1,577a, bovine liver, standard reference material. Sample dissolution time was drastically reduced from 3-4 hours, using the conventional method, to approximately 8 minutes using the microwave-assisted wet acid digestion procedure.

Cadmium↗
PubMed1991

Direct calibration for determining aluminum in bone and soft tissues by graphite furnace atomic absorption spectrometry.

We describe a direct-calibration method for determining aluminum in bone and soft tissues by graphite furnace atomic absorption spectrometry. Aluminum in bone was determined in uncoated tubes, whereas the analytical performance in soft tissue analysis was markedly improved by using pyrolytically coated tubes with a L'vov platform and added calcium. The analytical imprecision (CV) was less than or equal to 5.4% for aluminium concentrations between 12 and 98 micrograms/L, and analytical recoveries of added analyte varied between 94.5% and 103.0%. Detection limits (2 SD of determinations of the zero standard) were 7 and 6 pg for bone and soft tissues, respectively. Characteristic masses (amounts of Al yielding an absorbance signal of 0.0044 A) were 9 and 8 pg, respectively.

Aluminum↗
PubMed1991

Improved sample preparation for accurate determination of low concentrations of lead in whole blood by graphite furnace analysis.

The effect of low concentrations of lead on pre- and post-natal growth and development is a current concern. We describe a simple method of sample preparation for direct determination of lead in whole blood by Zeeman graphite-furnace atomic absorption spectrometry. This procedure improves analytical precision and accuracy of lead determinations at low concentrations as compared with published furnace data. At blood lead concentrations of 0.25, 1.98, and 3.76 mumol/L, within-run CVs were 3.2%, 1.8%, and 1.4% respectively; between-run CVs were 7.3%, 2.9%, and 2.2%. Accuracy, as demonstrated by analytical recovery, ranged from 99% to 102%. Our reproducibility/accuracy score in the 1989 Quebec interlaboratory comparison program was 96% compared with the target, second best of 66 participating laboratories.

Adult↗
PubMed1990

Direct selenium determination in human whole blood by graphite furnace atomic absorption spectrometry with deuterium correction using a L'vov-platform, a Pd/Mg matrix modification and appropriate dilution.

A mixture of palladium/magnesium nitrate was used as matrix modifier in graphite furnace atomic absorption spectrometry for the direct determination of selenium in human whole blood Addition of HCl up to 0.2 M, a twenty-five fold diluted sample and an appropriate furnace program are necessary to eliminate the interference of iron. Reproducibility of less than 3% at the 95 micrograms/L level, a detection limit of 10 micrograms/L and good accuracy, as determined by intercomparison runs and recovery of spiked samples, are obtained. The proposed method can be used for analysing 4 blood samples per hour.

Deuterium↗
PubMed1990

Selenium concentration levels in whole blood of Belgian blood bank donors, as determined by direct graphite furnace atomic absorption spectrometry.

Direct graphite furnace atomic absorption spectrometry after appropriate sample dilution is applied to whole blood of Belgian blood bank donors from different geographical areas. Highest values were obtained for the northern part of the country (Flanders). Different consumption habits may explain the significant difference in selenium level found for the two cultural communities (Flemish and Walloon). No sex difference was obtained in both parts of the country and no influence of age was observed for the two communities. Values obtained are compared with literature data on whole blood selenium content for other European countries.

Adult↗
PubMedDate not supplied

Determination of copper, iron, and nickel in oils and fats by direct graphite furnace atomic absorption spectrometry: summary of collaborative study.

A collaborative study of a method for the determination of copper, iron, and nickel in edible oils and fats by direct graphite furnace atomic absorption spectrometry was recently conducted by the International Union of Pure and Applied Chemistry. The quantitation limits of the method are 5 micrograms/kg for copper and 10 micrograms/kg for iron and nickel. The method has been adopted official first action as an IUPAC-AOAC method.

Copper↗