| Records |
| Author |
György, K.; Ajtony, Z.; van Meel, K.; Van Grieken, R.; Czitrovszky, A.; Bencs, L. |
| Title |
Fast heating induced impulse halogenation of refractory sample components in electrothermal atomic absorption spectrometry by direct injection of a liquid halogenating agent |
Type |
A1 Journal article |
Year  |
2011 |
Publication |
Talanta : the international journal of pure and applied analytical chemistry |
Abbreviated Journal |
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| Volume |
85 |
Issue |
3 |
Pages |
1253-1259 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
A novel electrothermal atomic absorption spectrometry (ETAAS) method was developed for the halogenation of refractory sample components (Er, Nd and Nb) of lithium niobate (LiNbO3) and bismuth tellurite (Bi2TeO5) optical single crystals to overcome memory effects and carry-over. For this purpose, the cleaning step of a regular graphite furnace heating program was replaced with a halogenation cycle. In this cycle, after the graphite tube cooled to room temperature, a 20 μL aliquot of liquid carbon tetrachloride (CCl4) was dispensed with a conventional autosampler into the graphite tube. The CCl4 was partially dried at 80 °C under the mini-flow (40 cm3 min−1) condition of the Ar internal furnace gas (IFG), then the residue was decomposed (pyrolyzed) by fast furnace heating at 19002100 °C under interrupted flow of the IFG. This step was followed by a clean-out stage at 2100 °C under the maximum flow of the IFG. The advantage of the present method is that it does not require any alteration to the graphite furnace gas supply system in contrast to most of the formerly introduced halogenation techniques. The effectiveness of the halogenation method was verified with the determination of Er and Nd dopants in the optical crystals. In these analyses, a sensitivity decrease was observed, which was likely due to the enhanced deterioration of the graphite tube surface. Therefore, the application of mathematical correction (resloping) of the calibration was also required. The calibration curves were linear up to 1.5 and 10 μmol L−1 for Er and Nd, respectively. Characteristic masses of 18 and 241 pg and the limit of detection (LOD) values of 0.017 and 0.27 μmol L−1 were found for Er and Nd, respectively. These LOD data correspond to 0.68 μmol mol−1 Er and 11 μmol mol−1 Nd in solid bismuth tellurite samples. The analytical results were compared with those obtained by a conventional ETAAS method and validated with X-ray fluorescence spectrometry analysis. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000294092800006 |
Publication Date |
2011-05-27 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0039-9140; 1873-3573 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
no |
| Call Number |
UA @ admin @ c:irua:91721 |
Serial |
7960 |
| Permanent link to this record |
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| Author |
Ajtony, Z.; Szoboszlai, N.; Bella, Z.; Bolla, S.; Szakál, P.; Bencs, L. |
| Title |
Determination of total selenium content in cereals and bakery products by flow injection hydride generation graphite furnace atomic absorption spectrometry applying in-situ trapping on iridium-treated graphite platforms |
Type |
A1 Journal article |
| Year |
2005 |
Publication |
Microchimica acta |
Abbreviated Journal |
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| Volume |
150 |
Issue |
1 |
Pages |
1-8 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
A flow injection hydride generation graphite furnace atomic absorption spectrometric (FI-HG-GFAAS) method was applied to the determination of Se in Se-doped and undoped cereals and bakery products. For the purpose of doping, the soils used for the cultivation of the cereals were dosed with Se- doped foliar fertilizers. The samples were dissolved in a mixture of HNO(3) and H(2)O(2) solutions using micro-waveassisted digestion. The decomposition of H(2)Se generated from the sample solutions and the trapping of elemental Se were performed at a temperature of 300 degrees C on an Ir-pretreated integrated graphite platform of a transversally heated graphite atomizer(THGA). For release of the trapped Se within a fairly short atomization time (5s), an atomization temperature of 2200 degrees C was observed to be optimal. The overall efficiency of hydride generation, transport and trapping was similar to 86%. The upper limit of the linear dynamic range of calibration was 10 mu gL(-1), which corresponds to 0.5 mu g g(-1) for solid samples. Recovery of the samples spiked with Se(VI) solutions was found to be 93 +/- 6% on average. The relative standard deviation of the determinations was less than 8%. The limit of detection was found to be 0.06 mu gL(-1), corresponding to 3 ng g(-1) for solid samples. The accuracy of the method was verified with the use of IAEA-155 ( whey powder) certified reference material. End-capped THGA tubes resulted in an extension of the linear calibration range compared to that of standard THGAs. The Se content in bakery products made of undoped cereals ranged from 7.7 to 68 ng g(-1) ( wet weight) in 18 samples, whereas the Se content of the corresponding cereals was found to be below 100 ng g(-1) ( wet weight). The Se level of cereals grown on soils treated with Se- doped fertilizers ranged from 128 to 1046 ng g(-1) ( wet weight), and it depended linearly on the Se concentration of the corresponding foliar fertilizer. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000229219900001 |
Publication Date |
2005-03-28 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0026-3672; 1436-5073 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
no |
| Call Number |
UA @ admin @ c:irua:94727 |
Serial |
7791 |
| Permanent link to this record |
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| Author |
Bencs, L.; Szakács, O.; Szoboszlai, N.; Ajtony, Z.; Bozsai, G. |
| Title |
Characteristics of atomic absorption calibration curves with the transversely heated graphite furnace |
Type |
A1 Journal article |
| Year |
2003 |
Publication |
Journal of analytical atomic spectrometry |
Abbreviated Journal |
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| Volume |
18 |
Issue |
2 |
Pages |
105-110 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Calibration curves with two quasi-linear sections ("double sloping'') were observed for the medium volatile elements, Cr and Cu, with the use of a SIMAA 6000 graphite furnace atomic absorption spectrometer under interrupted internal gas flow conditions. If a standard transversally heated graphite atomizer (THGA) tube was shortened by 0.5 mm at both of its ends, (i.e. the gaps were enlarged between graphite furnace housing and tube ends), a stronger declination of the calibration curves resulted. Elements with fairly high diffusion coefficients (>5.8 cm(2) s(-1)) and with short appearance time of their transients (<0.6 s), such as Cr and Cu, have shown the most characteristic sensitivity drop towards higher concentrations. This anomalous feature could be eliminated in three different ways; (1) by applying end-capped THGA tubes, (2) using mini-flow (50 cm(3) min(-1)) conditions during the atomization stage, and (3) by adding Pd-Mg chemical modifier. For the low volatile Mo and V, the calibration curves had no irregular shape. For Ag, Co, Cr, Cu, Mn and Ni, the mini-flow settings improved the linearity of the calibration curves and extended the upper limit of the linear calibration range by a factor of 1.5-2.0. The irregular characteristic of the analytical curves was interpreted as an increased vapour loss at higher analyte concentrations through the opened ends of the standard THGA tubes. This vapour loss was associated with the significantly diverse expulsion velocities of atoms, caused by the difference in temperature and concentration gradients, when evaporating amounts of analytes with more than one order of magnitude difference. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000180666600003 |
Publication Date |
2003-01-28 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0267-9477 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
no |
| Call Number |
UA @ admin @ c:irua:103320 |
Serial |
7606 |
| Permanent link to this record |
