نتایج جستجو برای: graphite furnace atomic absorption spectrometry
تعداد نتایج: 324535 فیلتر نتایج به سال:
Slurry sampling graphite furnace atomic absorption spectrometry technique was applied for the determination of Bi in environmental samples. The study focused on the effect of Zr, Ti, Nb and W carbides, as permanent modifiers, on the Bi signal. Because of its highest thermal and chemical stability and ability to substantially increase Bi signal, NbC was chosen as the most effective modifier. The...
A coprecipitation method with ytterbium hydroxide was studied for the determination of cadmium in water samples by graphite-furnace atomic absorption spectrometry. Up to 40 ng of cadmium in water samples was quantitatively coprecipitated with ytterbium hydroxide at pH 8.0-11.2. The concentration factor was 100 fold. The coprecipitated cadmium was sensitively determined without any influence of ...
A method is proposed for the solvent extraction of cadmium using 1,5-bis(di-2-pyridylmethylene)thiocarbohydrazide (DPTH) as extractant. The optimum extraction conditions were evaluated from a critical study of the effect of pH, concentration of extractant, shaking time and ionic strength. The maximum volume ratio of the aqueous to organic phase was 30:1 for a single-stage extraction of99-100% o...
This study describes and compares two methods of atomic absorption spectrometry (AAS) for the selenium (Se) analysis in food: electrothermal AAS (ET AAS) and hydride generation method of AAS (HG AAS). The accuracy of the two methods was established by analysing two biological reference materials: Wheat Flour 1567a and Bovine Liver 1577b from the National Institute of Standards and Technology, U...
Coprecipitation with terbium hydroxide quantitatively recovered trace amounts of chromium(III), copper(II) and lead(II) at pH 8.4 - 10.8, 8.0 - 11.5 and 8.7 - 11.5, respectively. The precipitate was dissolved in 0.85 mol dm(-3) nitric acid, and the analytes were determined by graphite-furnace atomic absorption spectrometry (GF-AAS). The presence of terbium (up to 7 g dm(-3)) did not interfere w...
The concentrations of some metals (Cu, Zn, Fe, Pb) in human placentas at term in two populations living in polluted (Krakow, n = 10) and non-polluted (Bieszczady, n = 13) areas were investigated by means of graphite furnace--or flame atomic absorption spectrometry (GF-AAS or F-AAS). The concentrations of Cu, Fe and Pb were higher in Krakow vs. Bieszczady, while Zn concentration was lower, but t...
A preconcentration system for multi-element electrothermal atomic absorption spectrometry was developed with a microcolumn packed with a chelating resin. The proposed method was applied successfully to the simultaneous determination of Co, Ni and Cu in seawater. A sample volume of 2 ml was required for the analysis. Retention of metal ions as a complex on the microcolumn was achieved by using M...
This paper proposes a low cost, simple, fast method for determining Ni and Cd in biodiesel samples by graphite furnace atomic absorption spectrometry (GFAAS). The method was evaluated in biodiesel from different sources. Tungsten was used as a permanent modifier and the samples were prepared in the form of microemulsions, by mixing about 0.5 g of biodiesel with 5 g of surfactant (Triton X-100) ...
Serum lead concentrations measured by stable isotope dilution with a thermal ionization mass spectrometer and blood lead concentrations measured by graphite furnace atomic absorption spectrophotometry are reported for 73 women of child bearing age resident in Los Angeles, California. The two quantities are related by the line y=0.00030+0.00241x (r=0.83), where y is serum lead concentration and ...
AIMS Levels of antioxidants such as folic acid and selenium decrease in dams exposed to ethanol during gestation and lactation, affecting their antioxidant status, their reproductive function and consequently the health of their progeny. We will study whether a Se (0.5 p.p.m.) plus folic acid (8 p.p.m.) supplemented diet administered to ethanol-exposed dams and male rats prevents the effects pr...
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