Thermal stability and spatial distribution of sodium chloride alone and in the presence of several metal salts on a graphite platform

Castro, M.A.; Feo, J. C.; Aller, A. J.

doi:10.1039/b209092a

Cited by 10 publications

(9 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This lack of effectiveness of protons in eliminating NaCl interference can be explained as being due to the high affinity of Pd for chlorine. 44 The above is particularly shown in Fig. 7, where the coexistence of sodium, chlorine and palladium on the graphite surface is evident.…”

Section: Efficiency Of Chemical Modifiers To Overcome Sodium Chloridementioning

confidence: 79%

Nickel as a Chemical Modifier for Sensitivity Enhancement and Fast Atomization Processes in Electrothermal Atomic Absorption Spectrometric Determination of Cadmium in Biological and Environmental Samples

et al. 2003

Self Cite

View full text Add to dashboard Cite

A systematic study of the efficiency of protons, Ni, Pd and Th as chemical modifiers for the determination of cadmium by electrothermal atomic absorption spectrometry (ETAAS) using fast temperature programs was made for platform atomization. A comparison was made in terms of the salt type, absorbance-time profiles and elimination of the sodium chloride interference. The results were adapted to develop a method for the ETAAS determination of cadmium in biological and environmental samples. The highest sensitivity to determine cadmium in biological and environmental samples was obtained using nickel (together with protons) as a chemical modifier. The accuracy of the method was tested by the determination of cadmium in different certified reference materials. The best detection limit and the characteristic mass of Cd were found to be 0.03 ng mL -1 and 0.35 pg, respectively.

show abstract

Section: Efficiency Of Chemical Modifiers To Overcome Sodium Chloridementioning

confidence: 79%

Nickel as a Chemical Modifier for Sensitivity Enhancement and Fast Atomization Processes in Electrothermal Atomic Absorption Spectrometric Determination of Cadmium in Biological and Environmental Samples

et al. 2003

Self Cite

View full text Add to dashboard Cite

show abstract

“…The operation of the CTF-188 atomiser and calibration of the temperature settings with an optical pyrometer have been described previously. 16,[20][21][22] Standard uncoated rectangular graphite tubes, and standard pyrolytic graphite coated graphite platforms and standard uncoated non-pyrolytic graphite platforms were used for atomization. The platform was inserted into the tube via a slot along the side of the tube, below the sample injection hole (Fig.…”

Section: Methodsmentioning

confidence: 99%

“…Electron probe techniques have proved to be very powerful tools for morphological visualization and chemical identification of solid micro-particles on the surface of graphite platforms. [15][16][17][18][19][20][21][22] However, the information derived mainly concerns the major transformations experienced by the matrix components and/or chemical modifiers in the injected solution, and only relatively high concentrations of the analyte. Other authors have used alternative techniques including Rutherford backscattering, synchrotron X-ray absorption spectroscopy, and mass spectrometry, among others, [23][24][25][26] for evaluation of condensed-phase species on a graphite platform over a shorter temperature range than considered in this study.…”

Section: Introductionmentioning

confidence: 99%

Spectrometric study of condensed phase species of thorium- and palladium-based modifiers in a complex matrix for electrothermal atomic absorption spectrometry

Castro

Aller

McCabe

et al. 2007

J. Anal. At. Spectrom.

Self Cite

View full text Add to dashboard Cite

The chemical and morphological transformations of condensed phase species of a thorium-based modifier were studied over the temperature range 200-2500 1C, without and with the presence of aluminium and silicon as matrix components, and in some instances, arsenic as an analyte element. A similar study was also conducted with palladium as the modifier, for comparison. Results were derived using scanning electron microscopy (SEM), energy dispersive (ED) X-ray spectrometry, Raman microanalysis and attenuated total reflectance (ATR) Fourier transforminfrared (FT-IR) spectrometry. Comparable results were found using pyrolytic and non-pyrolytic graphite platforms, with processes occurring at slightly higher temperatures on the pyrolytic graphite platform. With thorium as the modifier, metal oxides were the predominant species on the platform surface at relatively low temperatures (o1500 1C), whereas metal phases became prevalent at high temperatures, when thorium and aluminium tended to behave independently from one other. Some spatial variations in the composition of the salt residues on different regions of the platform were observed (from the region closest to the slot in the tube, to the region furthest from the slot). Nonetheless, thorium metal remained on the graphite platform to higher temperatures than did aluminium metal. In the presence of arsenic, the existence of mixtures of thorium and arsenic oxides, just before the appearance temperature of gas phase arsenic atoms, was confirmed by SEM studies, ED X-ray spectra and Raman microanalysis. This suggests that any modifying effect of thorium on arsenic occurs while the modifier is in the oxide phase rather than in the metal phase. The presence of silicon added as silica, did not influence significantly the thermochemical behaviour of mixtures of thorium and aluminium. However, coexistence of silicon and arsenic oxides at the appearance temperature of the atomic absorption signal of arsenic was obtained, confirming that silicon can act as an internal modifier for arsenic. In the presence of palladium, aluminium exhibited greater interaction with the modifier; consequently, aluminium metal was retained on the platform surface to higher temperatures than thorium, which could explain how interference effects of aluminium on e.g. arsenic are avoided or reduced. Similarly, there was evidence for interaction of palladium and arsenic in the reduced state. However, when aluminium and silicon were present, the transformation of the palladium oxide to the metallic state was affected, which could diminish the modifying benefits of palladium for arsenic in the presence of aluminium.

show abstract

“…By increasing the concentration of these salts from 0.001% to 1% (w/v), there is an increase in recovery initially around 0.01% concentration of the matrix and then, there is a reduction and with 1% salt, recovery is almost nil in some cases. It has been reported that NaCl can be retained in the platform up to 950°C and that Pd would stabilize NaCl to even higher temperature [34]. Therefore, loss of Ge in the presence of a Pd modifier can be explained by the release of chloride during atomization.…”

Section: Effect Of Conventional Pd-mg Modifier On Ge In the Presence mentioning

confidence: 98%

Studies on reduction of chloride matrix interferences on determination of germanium using zirconium–ruthenium and palladium–magnesium modifiers by electrothermal atomic absorption spectrometry

Meeravali

Reddy

Kumar

2007

Spectrochimica Acta Part B: Atomic Spectroscopy

View full text Add to dashboard Cite

Thermal stability and spatial distribution of sodium chloride alone and in the presence of several metal salts on a graphite platform

Cited by 10 publications

References 67 publications

Nickel as a Chemical Modifier for Sensitivity Enhancement and Fast Atomization Processes in Electrothermal Atomic Absorption Spectrometric Determination of Cadmium in Biological and Environmental Samples

Nickel as a Chemical Modifier for Sensitivity Enhancement and Fast Atomization Processes in Electrothermal Atomic Absorption Spectrometric Determination of Cadmium in Biological and Environmental Samples

Spectrometric study of condensed phase species of thorium- and palladium-based modifiers in a complex matrix for electrothermal atomic absorption spectrometry

Studies on reduction of chloride matrix interferences on determination of germanium using zirconium–ruthenium and palladium–magnesium modifiers by electrothermal atomic absorption spectrometry

Contact Info

Product

Resources

About