Atomization mechanisms of silicon in a graphite furnace atomizer

Abstract

An attempt has been made to identify molecular species that are formed during the atomization cycle of Si in electrothermal atomic absorption spectrometry. Clear evidence has been obtained that two molecular species are formed, presumably SiO and Sic2. In order to gain an insight into the reactions whereby these molecular species are formed and Si atoms from these species, the effect on the signal of the addition of 02, C 0 2 , CO and H2 to the purge gas was investigated. By using the results of these experiments, a mechanism for the atomization of Si in the graphite furnace atomizer is proposed.

Effect on silicon atomization of tungsten-assisted modification of atomic-absorption spectrometer graphite furnaces

“…The appearance of two peaks can be explained in two ways. According to the literature, Si after ashing is found as oxides and carbides [26,30]. The oxides are atomized at lower temperatures than the carbides [26,29].…”

Direct determination of trace amounts of silicon in polyamides by means of solid sampling electrothermal vaporization inductively coupled plasma mass spectrometry

“…1 a and b shows the blanks obtained (10 ml of ultra-pure water) when a vaporization temperature of 2400 uC is selected. The blank for the main isotope 28 Si 1 is too high (the number of counts s 21 exceeds the limit of the detector of 3000000). Hence, this isotope cannot be used for silicon determination at the nanogram level.…”

“…This effect does not occur if palladium is used and can be attributed to the formation of refractory silicon carbides as the tube deteriorates. 26,28 For all these reasons, the use of 1 mg of palladium was considered beneficial for the determination of silicon in the polyamides.…”

Determination of aluminum and silicon in bovine liver by graphite furnace atomic absorption spectrometry after dissolution with tetramethylammonium hydroxide

“…The behavior of Si in the graphite furnace is complex and not fully understood. 16,25,26 Due to its ability to produce refractory carbides and volatile oxides during the atomization cycle in the graphite furnace, the determination of Si by GFAAS can undergo a memory effect, matrix interference and have a relatively low sensitivity. 27 Attempts to overcome these problems usually involve the use of graphite tubes coated with carbides of metals and the use of chemical modiers 16 such as palladium that reduces losses due to volatilization during pyrolysis.…”