Mechanisms of vaporization for silver and gold using electrothermal atomization

Atomization Mechanisms of Gold from Thermally Decomposed and Crudely Roughened Pyrolytically Coated Graphite Furnaces Using Electrothermal Atomization

“…4 in ref. 7. Although a tendency of the E a to decrease as the concentration decreases was observed from the reference's data, a nearly constant E a (average value: 135 kJ mol -1 ) value was observed for the new PG furnace in this work.…”

“…2 In an electrothermal graphite furnace atomic absorption spectrometry, it has been reported by using kinetic analysis that the desorption of gold occurs from microdroplets as a solution deposition is used. [3][4][5][6] Fonseca and co-workers 7 reported that vaporization of gold and silver appears to occur from varying sizes of microdroplets or from adatoms, depending on the analytical conditions, such as dry and thermal pretreatment conditions, chemisorbed oxygen on the graphite surface and mechanically created active sites on the graphite surface. In the case of silver, although a tendency of the activation energy (E a ) for atomization to increase as the concentration increases was observed with a fractional order desorption, a constant E a was observed below 0.06 ng of silver, which is in agreement with the morphology of dispersed atoms with a first order desorption.…”

“…The kinetic order of atom release can be predicted from the concentration dependence of absorbance-time profile characteristics. 3,7 In the first order process, analyte desorption takes place from a monolayer of analyte atoms which are physically sorbed or chemisorbed onto the wall surface. In the fractional order process the analyte atoms are released from microdroplets.…”

Effect of the Surface Treatment of a Graphite Furnace with a Refractory Element (Hafnium, Titanium, Tungsten and Zirconium) by a One-Drop Coating Method on the Atomization Mechanism of Indium in Electrothermal Atomic Absorption Spectrometry

“…According to McNally and Holcombe as well as Fonseca et al, the process-controlling mechanism can be established from the specific dependence of the absorbance-time profiles on the analyte mass. 30,31 When the atomic absorption signals were measured over various indium concentrations with the W-and Zrtreated PG and NPG furnaces, typical atomic absorption profiles were found, as given in Fig. 3.…”

Pyrolytic and Non-Pyrolytic Boron Nitride Furnaces for Electrothermal Atomic Absorption Spectrometry

“…[7][8][9][10][11] The reducing atmosphere does not affect its integrated absorbance. 10,12 The sensitivity with the PBN tube furnace is better than that with the NBN one.…”