Analytical potential of non-resonance lines for the determination of palladium by graphite furnace atomic absorption spectrometry

Summary Palladium is determined by graphite furnaceatomic absorption spectrometry. 8 non-resonance lines were studied, 4 of which have not been previously reported. The peak shapes and parameters of non-resonance lines are somewhat different from those of the resonance lines. The sensitivity of non-resonance transitions is found to be strongly dependent on the atomization temperature, heating rate of the graphite furnace as well as flow rate and nature of the purge gas used. The peak area sensitivity of the 340.5 nm nonresonance line almost equals that of the 276.3 nm resonance line.

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Analytische Möglichkeiten der Nichtresonanz-Linien für die Palladiumbestimmung durch Graphitofen-AAS

Zusammenfassung 8 Nichtresonanz-Linien wurden untersucht, von denen über 4 zuvor noch nicht berichtet wurde. Die Peakform und Parameter dieser Linien zeigen gewisse Unterschiede gegenüber denjenigen von Resonanzlinien. Die Empfindlichkeit ist stark von der Atomisierungstemperatur, der Aufheizgeschwindigkeit sowie der Geschwindigkeit und Art des verwendeten Spülgases abhängig. Die Peakflächenempfindlichkeit der Nichtresonanz-Linie 340,5 nm ist derjenigen der Resonanz-Linie 276,3 nm fast gleich.

     

Determination of thallium in cadmium and lead by graphite-furnace atomic-absorption spectrometry with sample vaporization from a platform

When the sample is vaporized from the wall of a graphite furnace it is not possible to determine thallium in cadmium and lead by AAS without matrix matching of the standards. In the case of a lead matrix and vaporization from the wall, the thallium signal is barely distinguishable from the base-line. When the sample is vaporized from a platform, and the peak area is used for measurement, pure aqueous standards may be used for instrument calibration. The peak heights and areas of the thallium signals are considerably enhanced by vaporization from a platform (peak height 1.7-fold and peak area 2.6-fold in pure aqueous solutions as compared to vaporization from the wall). The enhancement factors are larger in presence of the cadmium or lead matrix since here the reduced interference also makes a contribution.     

Sensitivity enhancement of beryllium determination in graphite furnace-atomic absorption spectrometry by use of atomization under pressure

Microchimica Acta - Using pressurized atomization both peak height and area sensitivity of beryllium is considerably improved. The enhancement may probably be explained by the fact that the Lorentz...     

Critical Study of the Determination of Europium by Electrothermal Atomic Absorption Spectrometry

Europium may be determined by electrothermal atomic absorption spectrometry with good sensitivity when using procoated furnaces. The maximum allowable ashing temperature is 1600 °C and the optimal atomization temperature is 2600 °C. Similar results were obtained using two different atomizers and detection systems. At the wavelength used for the determination of europium, the background continuum emitted by the furnace is very strong. Care should be taken to eliminate scattering species from the windows of the furnace housing.     

Mössbauer study of rapidly solidified Al-Fe based amorphous alloys

Mössbauer spetroscopy and X-ray diffraction were used to study the structure of rapidly quenched Al₈₈Fe₅Y₇, Al₈₈Fe₄Y₇Sb₁ and Al₉₃Fe₅Sb₂ alloys. Sb addition diminishes the glass forming ability and results in precipitation of the stable AlSb compound. The X-ray amorphous Al₈₈Fe₅Y₇ alloy shows a short range order resembling to the Al₆Fe compound as it can be judged from the Mössbauer data.     

Influence of pressure on the determination of palladium by graphite furnace atomic absorption spectrometry using resonance and non-resonance lines

Atomization under pressure considerably influences the absolute and relative sensitivities of resonance and non-resonace lines. Whereas for resonance lines the peak height and area senstitivities decrease with increasing pressure, for non-resonance lines the sensitivity initially increases probably because the increase of the temperature of the atomic vapor compensates for the Lorentz broadening and the red shift. At higher pressures probably absorption line broadening and red shift effect become predominant so that the sensitivity of the non-resonance lines becomes poorer. In spite of this the relative sensitivity of the non-resonance lines as compared to the resonance lines under the same conditions. improves steadily with increasing pressure. It is possible that the absorption profiles of the resonance and the non-resonance lines are affected differently by pressure. The peak characterization times differ considerably for the resonance and non-resonance lines. Calibration curves become more linear with increasing pressure. The improvement is more pronounced for the resonance line.     

The influence of atomization pressure on the behaviour of aluminium in electrothermal atomic-absorption spectrometry

Pressurized atomization in argon purge gas considerably enhances the peak area in AAS determination of aluminium, owing to the decrease in the diffusion rate of atoms with increasing pressure. If lower heating rates are used, the diffusional loss mechanism becomes more important. Thus pressure then has an even more pronounced influence on signal strength. Atomization under pressure in argon purge gas is shown to be beneficial only for light elements. It can be expected that if instrumental matrix modification is made by using hydrogen as purge gas, increasing the atomization pressure may prove beneficial for all elements.     

Influence of Analyte Volatility and Ashing Temperature on the Absorbance—Atomization Pressure Relationship in Electrothermal Atomic Absorption Spectrometry. The Case of Arsenic. Some Facts and Speculations

Various fundamental and applied aspects of pressurized atomization are discussed. The graphite furnaces are shown to be non-isobar in space and time. This is determined by the non-isothermality in space and time. Volatile and non-volatile forms of the same element are shown to be influenced differently by pressure. The ashing temperature used also influences the behaviour of analytes vis à vis atomization pressure. It is suggested that furnace designs that avoid high pressures within the furnace during atomization may lead to an enhancement of sensitivity, at least in the case of volatile elements. The use of matrix modifiers may change the spectral conditions by altering the shape and profile of spectral lines. Our discussion refers only to the case when line sources of radiation are used.     

Influence of impurities on the band ferromagnetism

The influence of non-magnetic impurities on band ferromagnetism for an electron gas withδ-function interaction is investigated in the framework of the quantum field theory applied to phase transitions. The Hartree-Fock approximation is used for non-zero temperatures. An equation for the magnetizationM and the critical temperatureT F_c is obtained. It is found that the transition temperature is lowered by increasing impurity concentration. There exists a critical concentration which vanishes the ferromagnetism.     

Determination of silver by graphite furnace—atomic absorption spectrometry with atomization under pressure

Summary When determined with pressurized atomization silver shows a lower peak height sensitivity than under normal conditions. Peak area is less influenced by pressure. The peak parameters are somewhat changed as compared to normal atomization. Notable is the prolongation of the mean residence time and peak time. Interferences are reduced with atomization under pressure.The linearity of the calibration curves is extended with atomization under pressure.

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Silberbestimmung im Graphittiegel. Atomabsorptions-Spektrometrie nach Zerstäubung unter Druck

Zusammenfassung Bei Zerstäubung unter Druck zeigt Silber eine geringere Empfindlichkeit der Peak-Höhe. Die Peak-Fläche wird durch Druck weniger stark beeinflußt. Im Vergleich zur Normalzerstäubung sind die Peak-Parameter etwas verändert, die Störungen sind bei Zerstäubung unter Druck geringer, die Eichkurven verlaufen über größere Strecken geradlinig.