981 resultados para High-resolution continuum source flame atomic spectrometry


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Microwave-assisted acid decomposition, direct dilution in kerosene, and oil-in-water emulsion were evaluated as lubricating oil pretreatment procedures for Cu, Cr, Fe, Ni, Pb, Sb, and Zn determination by High-Resolution Continuum Source Flame Atomic Absorption Spectrometry (HR-CS FAAS). For wet digestion, results were compared with those obtained by Flame Atomic Absorption Spectrometry (FAAS). The ultrasound probe used in emulsions sonication contaminated samples with Cr, although better results have been observed for the other six elements in this condition. In general, recovery percentages ranging from 81-106%(Cu), 80-107%(Cr), 85-114%(Fe), 82-116%(Ni), 86-117%(Pb), 85-115%(Sb), and 81-114%(Zn) were obtained. The HR-CS FAAS showed to be faster and more sensitive than FAAS.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A simple method to determine Cu, Fe, Mn and Zn in single aliquots of medicinal plants by HR-CS FAAS is proposed. The main lines for Cu, Mn and Zn, and the alternate line measured at the wing of the main line for Fe at 248.327 nm allowed calibration within the 0.025 - 2.0 mg L-1 Cu, 1.0 - 20.0 mg L-1 Fe, 0.05 - 2.0 mg L-1 Mn, 0.025 - 0.75 mg L-1 Zn ranges. Nineteen medicinal plants and two certified plant reference materials were analyzed. Results were in agreement at a 95% confidence level (paired t-test) with reference values. Limits of detection were 0.12 μg L-1 Cu, 330 μg L-1 Fe, 1.42 μg L-1 Mn and 8.12 μg L-1 Zn. Relative standard deviations (n=12) were ≤ 3% for all analytes. Recoveries in the 89 - 105% (Cu), 95 - 108% (Fe), 94 - 107% (Mn), and 93 - 110% (Zn) ranges were obtained.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Solid-state M-L compounds, where M stands for bivalent Mn, Co, Ni, Cu and Zn and L is folate (C19H17N7O6), have been synthesized. Simultaneous thermogravimetry and differential scanning calorimetry (TG-DSC), X-ray powder diffractometry, infrared spectroscopy (FTIR), TG-DSC coupled to FTIR, elemental analysis and high-resolution continuum source flame atomic absorption spectrometry technique (HR-CS FAAS) were used to characterize and to study the thermal behaviour of these compounds. The results provided information concerning the composition, dehydration, thermal stability and thermal decomposition. © 2013 Akadémiai Kiadó, Budapest, Hungary.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This work describes instrumental strategies for the determination of Mn in a wide range concentration by high-resolution continuum source flame atomic absorption spectrometry technique (HR-CS F AAS) by means of different atomic lines (primary at 279.482 nm, secondary at 403.075 nm and alternative at 209.250 nm). These lines provided complementary concentration intervals, and large sample dilutions became unnecessary. The proposed method was applied to tap water, metal alloy certified material and foliar fertilizer. Accuracy for secondary line were evaluated by tests of significance (t Student test) with reference materials from the Institute of Technological Research of São Paulo, and the results were in agreement at the 95% confidence level. For primary and alternative lines, recovery is were in the 84-116% range and the RSD were 6.1% for all wavelengths. Analytical curves in the 0.1 - 2.0 mg L-1 (279.482 nm), 2.0 - 25 mg L-1 (403.075 nm), 25 - 500 mg L-1 (209.250 nm) intervals were obtained with linear correlation coefficient better than 0.9991. The detection limits were 3.3x10-3 mg L-1 (279.482 nm), 7.4 x 10-3 mg L-1 (403.075 nm), 3.9 mg L- 1 (209.250 nm). The found Mn concentrations were < 3.3x10-3 mg L-1 (tap water), 1.00 ± 0.04 (% m/m) (alloy IPT 25), 7235 ± 175 mg L-1 (foliar fertilizer 1), 4990 ± 132 mg L-1 (foliar fertilizer 2). A method was developed to detect interference of Fe in the Mn primary line (279.482 nm) using the ratio of absorbances of other lines of the triplet (279.827 nm and 280,108 nm).

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)