Effects of atomization surfaces and modifiers on the kinetics of copper atomization in electrothermal atomic absorption spectrometry

Álvarez, María Asunción Aneas; Carrión, Nereida; Gutiérrez, Héctor

doi:10.1016/0584-8547(96)01509-1

Cited by 15 publications

(9 citation statements)

References 33 publications

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“…The lifetime of the graphite tube was equivalent to 720 firings. Considering the complexity of the biological matrices, the tube's service life with the proposed method is acceptable when compared with other methods described in the literature [16,[20][21][22]. After optimization, the accuracy of proposed method for determination of copper was investigated in slurries of four feed samples enriched with this micronutrient and one standard reference material of corn bran (RM 8433, contained 2.47 ± 0.40 mg kg -1 ), from National Institute of Standards and Technology) that is used in the diet of fish ( Table 3).…”

Section: Obtainment Of the Analytical Curvesmentioning

confidence: 84%

“…After cryogenic grinding, 5 mg of samples of biological material (fish feed or feces) were transferred directly to the containers of the spectrometer's autosampler, to which were added 5 lL of suprapure nitric acid 14 mol L -1 , 50 lL of Triton X-100 at 1% v/v and 945 lL of ultrapure water [14][15][16][17][18][19][20][21][22]. The slurry samples of biological material were then sonicated for 40 s directly in the autosampler's containers.…”

Section: Preparation Of Slurry Samplesmentioning

confidence: 99%

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Determination of copper in fish feed by graphite furnace atomic absorption spectrometry using slurry sampling

Neves

Moraes

Silva

et al. 2008

Sens. & Instrumen. Food Qual.

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The present work develops and optimizes a method to determine copper in samples of feces and fish feed by graphite furnace atomic absorption spectrometry (GFAAS) through the direct introduction of slurries of the samples into the spectrometer's graphite tube coated internally with metallic rhodium and tungsten carbide that acts as chemical modifiers. The limits of detection (LOD) and quantification (LOQ) calculated for 20 readings of the blank of the standard slurries (0.50% m/v of feces or feed devoid of copper) were 0.24 and 0.79 lg L -1 for the standard feces slurries and 0.26 and 0.87 lg L -1 for the standard feed slurries. The proposed method was applied in studies of absorption of copper in different fish feeds and their results proved compatible with that obtained from samples mineralized by acid digestion using microwave oven.

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Section: Obtainment Of the Analytical Curvesmentioning

confidence: 84%

Section: Preparation Of Slurry Samplesmentioning

confidence: 99%

Determination of copper in fish feed by graphite furnace atomic absorption spectrometry using slurry sampling

Neves

Moraes

Silva

et al. 2008

Sens. & Instrumen. Food Qual.

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show abstract

“…Rohrer and Wegscheider [25] give the value 10 12 s À 1 as the lower limit of weak surface interactions, which actually agrees to our considerations. Alvarez et al [26,27] give data about magnitude of preexponential factor obtained for Cu and Ni, but their interpretation is opposite. It should be noted that when the atomization temperature changes (and therefore the heating rate changes also) the certain changes in the investigated parameters could be observed ( Table 1).…”

Section: Quantitative Characterization Of Atomic Absorption Signals Omentioning

confidence: 89%

Simulation of atomic absorption signals: A kinetic model with two independent sources

Buhay

Rogulsky

Kulik

et al. 2005

Spectrochimica Acta Part B: Atomic Spectroscopy

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“…In [16,17], the values for the pre-exponential factors for copper and nickel are given, but with the opposite interpretation.…”

Section: Introductionmentioning

confidence: 97%

Kinetic Model of Entry of Free Atoms into an Electrothermal Atomizer

et al. 2005

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A kinetic phenomenological model of the processes of atomization for atomic-absorptional spectrometry with electrothermal atomization that is based on solution of a one-dimensional equation of diffusion with two independent sources is suggested. The model takes into account the processes occurring both on the surface of a graphite furnace and inside its wall. The proposed model is used for describing the electrothermal atomization of copper and zinc.Introduction. It is known that in the method of atomic-absorption spectrometry with electrothermal atomization (ETAAS), a metered amount of the sample analyzed is delivered onto the graphite surface of a furnace (or platform) on which its thermal treatment and atomization occur. A liquid sample not only spreads over the surface but also penetrates into the pores of the furnace material under the action of capillary forces, as a result of which the conditions of sample atomization are altered [1,2]. It is evident that here the state and properties of the graphite surface play a significant role.It has been shown earlier [2-6] that the form of the analytical signal depends substantially on the state of the furnace surface and the degree of its wear, and the necessity of creating a model that would take into account penetration of a sample into the surface pores has been substantiated [2]. Such a model may also be of use in studying the influence of permanent modifiers on the mechanism of atomization [7].To construct a correct phenomenological model of sample atomization in a graphite furnace it is necessary to consider two sources of free atoms: one on the furnace surface and the other inside its walls. The present work is devoted to the solution of this problem. For experimental checking of the model, we selected copper and zinc, the mechanisms of atomization of which are different.Theory. In constructing the model, we use some facts and assumptions.1) The atomic absorption A(t) is proportional to the mass M(t) of the free atoms that are present in the analytical volume of the furnace in a gas phase.2) In delivering metered amounts of a sample into the furnace (or onto the platform), a portion of the liquid sample penetrates into graphite under the action of capillary forces [1, 2]. As the total initial mass of the atoms M 0 placed inside an atomizer we take the mass of the atoms participating in formation of an analytical signal. It can be represented as the sum of the masses of atoms on the surface of the furnace and inside its pores:

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Effects of atomization surfaces and modifiers on the kinetics of copper atomization in electrothermal atomic absorption spectrometry

Cited by 15 publications

References 33 publications

Determination of copper in fish feed by graphite furnace atomic absorption spectrometry using slurry sampling

Determination of copper in fish feed by graphite furnace atomic absorption spectrometry using slurry sampling

Simulation of atomic absorption signals: A kinetic model with two independent sources

Kinetic Model of Entry of Free Atoms into an Electrothermal Atomizer

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