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Selected papers from the latest issue:Boltzmann statistical consideration on the excitation mechanism of iron atomic lines emitted from glow discharge plasmas
15 October 2011, 21:59:56
Publication year: 2011
Source: Spectrochimica Acta Part B: Atomic Spectroscopy, Available online 15 October 2011
Lei Zhang, Shunsuke Kashiwakura, Kazuaki Wagatsuma
A Boltzmann plot for many iron atomic lines having excitation energies of 3.3 - 6.9 eV was investigated in glow discharge plasmas when argon or neon was employed as the plasma gas. The plot did not show a linear relationship over a wide range of the excitation energy, but showed that the emission lines having higher excitation energies largely deviated from a normal Boltzmann distribution whereas those having low excitation energies (3.3 - 4.3 eV) well followed it. This result would be derived from an overpopulation among the corresponding energy levels. A probable reason for this is that excitations for the high-lying excited levels would be caused predominantly through a Penning-type collision with the metastable atom of argon or neon, followed by recombination with an electron and then stepwise de-excitations which can populate the excited energy levels just below the ionization limit of iron atom. The non-thermal excitation occurred more actively in the argon plasma rather than the neon plasma, because of a difference in the number density between the argon and the neon metastables. The Boltzmann plots yields important information on the reason why lots of Fe I lines assigned to high-lying excited levels can be emitted from glow discharge plasmas.
Source: Spectrochimica Acta Part B: Atomic Spectroscopy, Available online 15 October 2011
Lei Zhang, Shunsuke Kashiwakura, Kazuaki Wagatsuma
A Boltzmann plot for many iron atomic lines having excitation energies of 3.3 - 6.9 eV was investigated in glow discharge plasmas when argon or neon was employed as the plasma gas. The plot did not show a linear relationship over a wide range of the excitation energy, but showed that the emission lines having higher excitation energies largely deviated from a normal Boltzmann distribution whereas those having low excitation energies (3.3 - 4.3 eV) well followed it. This result would be derived from an overpopulation among the corresponding energy levels. A probable reason for this is that excitations for the high-lying excited levels would be caused predominantly through a Penning-type collision with the metastable atom of argon or neon, followed by recombination with an electron and then stepwise de-excitations which can populate the excited energy levels just below the ionization limit of iron atom. The non-thermal excitation occurred more actively in the argon plasma rather than the neon plasma, because of a difference in the number density between the argon and the neon metastables. The Boltzmann plots yields important information on the reason why lots of Fe I lines assigned to high-lying excited levels can be emitted from glow discharge plasmas.
Highlights
► This paper demonstrates the excitation mechanism on excited energy levels of iron atom having higher excitation energies from a glow discharge plasma, by analyzing a Boltzmann distribution among lots of Fe I lines, which suggests an excitation scheme on the overpopulation of high-lying energy levels of iron atom through Penning-type collisions with argon and neon metastable atoms.An approach for the mechanism of nickel interferences in hydride generation atomic absorption spectrometric determination of arsenic and antimony
15 October 2011, 21:59:56
Publication year: 2011
Source: Spectrochimica Acta Part B: Atomic Spectroscopy, Available online 14 October 2011
Emur Henden, Yasemin İşlek, Miray Kavas, Nur Aksuner, Onur Yayayürük, ...
Studies have been carried out to clarify the mechanism of nickel interferences in the hydride generation atomic absorption spectrometric determination of arsenic and antimony. The most serious nickel interferences are observed when nickel/nickel boride nanoparticles are produced during NaBH4reduction. In this study these particles have been observed to have diameters of less than 40 nm and sorb As(III), As(V) and Sb(III) species rather than arsine and stibine generated as so far assumed. Bulk chemical composition and surface structure of these nanoparticals were studied and it was found that if the NaBH4reduction is carried out while passing nitrogen through the solution the black nanoparticles were composed of Ni2B and, if the reduction is carried out under air the black nanoparticles were found to consist of Ni3B or possibly a mixture of Ni(0) and Ni2B. Surface analysis studies with scanning electron microscopy, energy dispersive x-ray spectrometry, x-ray photoelectron spectrometry and x-ray diffraction analysis have shown that the particles have amorphous structure consisting of Ni(0), Ni2B, Ni3B and Ni(OH)2. However, sorption studies have shown that Ni(0) and Ni(OH)2do not sorb the analyte ions and arsine and stibine significantly.
Source: Spectrochimica Acta Part B: Atomic Spectroscopy, Available online 14 October 2011
Emur Henden, Yasemin İşlek, Miray Kavas, Nur Aksuner, Onur Yayayürük, ...
Studies have been carried out to clarify the mechanism of nickel interferences in the hydride generation atomic absorption spectrometric determination of arsenic and antimony. The most serious nickel interferences are observed when nickel/nickel boride nanoparticles are produced during NaBH4reduction. In this study these particles have been observed to have diameters of less than 40 nm and sorb As(III), As(V) and Sb(III) species rather than arsine and stibine generated as so far assumed. Bulk chemical composition and surface structure of these nanoparticals were studied and it was found that if the NaBH4reduction is carried out while passing nitrogen through the solution the black nanoparticles were composed of Ni2B and, if the reduction is carried out under air the black nanoparticles were found to consist of Ni3B or possibly a mixture of Ni(0) and Ni2B. Surface analysis studies with scanning electron microscopy, energy dispersive x-ray spectrometry, x-ray photoelectron spectrometry and x-ray diffraction analysis have shown that the particles have amorphous structure consisting of Ni(0), Ni2B, Ni3B and Ni(OH)2. However, sorption studies have shown that Ni(0) and Ni(OH)2do not sorb the analyte ions and arsine and stibine significantly.
Highlights
► Arsine and stibine are not sorbed by Ni/NixB nanoparticles ► Ni/NixB nanoparticles sorb As(III), As(V) and Sb(III) ions ► Ni interference in HGAAS is due to the sorption of the analyte ions by Ni/NixBAn approach for the mechanism of nickel interferences in hydride generation atomic absorption spectrometric determination of arsenic and antimony
14 October 2011, 22:00:51
Publication year: 2011
Source: Spectrochimica Acta Part B: Atomic Spectroscopy, Available online 14 October 2011
Emur Henden, Yasemin İşlek, Miray Kavas, Nur Aksuner, Onur Yayayürük, ...
Studies have been carried out to clarify the mechanism of nickel interferences in the hydride generation atomic absorption spectrometric determination of arsenic and antimony. The most serious nickel interferences are observed when nickel/nickel boride nanoparticles are produced during NaBH4reduction. In this study these particles have been observed to have diameters of less than 40 nm and sorb As(III), As(V) and Sb(III) species rather than arsine and stibine generated as so far assumed. Bulk chemical composition and surface structure of these nanoparticals were studied and it was found that if the NaBH4reduction is carried out while passing nitrogen through the solution the black nanoparticles were composed of Ni2B and, if the reduction is carried out under air the black nanoparticles were found to consist of Ni3B or possibly a mixture of Ni(0) and Ni2B. Surface analysis studies with scanning electron microscopy, energy dispersive x-ray spectrometry, x-ray photoelectron spectrometry and x-ray diffraction analysis have shown that the particles have amorphous structure consisting of Ni(0), Ni2B, Ni3B and Ni(OH)2. However, sorption studies have shown that Ni(0) and Ni(OH)2do not sorb the analyte ions and arsine and stibine significantly.
Source: Spectrochimica Acta Part B: Atomic Spectroscopy, Available online 14 October 2011
Emur Henden, Yasemin İşlek, Miray Kavas, Nur Aksuner, Onur Yayayürük, ...
Studies have been carried out to clarify the mechanism of nickel interferences in the hydride generation atomic absorption spectrometric determination of arsenic and antimony. The most serious nickel interferences are observed when nickel/nickel boride nanoparticles are produced during NaBH4reduction. In this study these particles have been observed to have diameters of less than 40 nm and sorb As(III), As(V) and Sb(III) species rather than arsine and stibine generated as so far assumed. Bulk chemical composition and surface structure of these nanoparticals were studied and it was found that if the NaBH4reduction is carried out while passing nitrogen through the solution the black nanoparticles were composed of Ni2B and, if the reduction is carried out under air the black nanoparticles were found to consist of Ni3B or possibly a mixture of Ni(0) and Ni2B. Surface analysis studies with scanning electron microscopy, energy dispersive x-ray spectrometry, x-ray photoelectron spectrometry and x-ray diffraction analysis have shown that the particles have amorphous structure consisting of Ni(0), Ni2B, Ni3B and Ni(OH)2. However, sorption studies have shown that Ni(0) and Ni(OH)2do not sorb the analyte ions and arsine and stibine significantly.
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