Graphite tube furnace

Evenson, M. A. and Pendergast, D. D. "Rapid Ultramicro Direct Determination of Erythrocyte Lead Concentration by Atomic Absorption Spectrophotometry with Use of a Graphite Tube Furnace". Clin. Chem. (1974), 20, 163-171. 

Lundgren, 6. and Johansson, 6. "A Temperature-Controlled Graphite Tube Furnace for the Determination of Trace Metals in Solid Biological Tissue . Talanta (1974), 21, 257-264. 

The graphite furnace method of atomization utilizes a small graphite tube furnace to electrically heat rapidly a small volume of the analyte solution contained inside to a temperature that eventually causes atomization. 

Even a technique of higher detection power as ET-AAS may require some sort of previous analyte enrichment for difficult elements. In the determination of As and Se in mineral waters described by Hudnik and Gomiscek [23], coprecipitation of both elements on hydrated Fe(III) oxide was employed to improve LoDs, otherwise impaired by matrix effects. A graphite tube furnace was the atomization cell, with the atomic vapor sampled with element electrodeless discharge lamps. After treatment of the sample with Fe(III) solution at the appropriate pH, the oxide precipitate was filtered and dissolved and the solution volume reduced to 5 mL of 0.2 M H2SO4. Ten-microliter volume aliquots of sample and standard solutions were injected into the furnace. Reported LoDs were 0.2 and 0.5 p,g l-1 for As and Se, respectively. 

Sensitivities of Sc, Y and REE elements as obtained with a pyrolytic graphite coated graphite tube furnace using the Hitachi Z-9000 simultaneous multi-element atomic absorption spectrometer and comparison with some... 

Operating conditions. AAS-device with graphite tube furnace and deuterium background corrector. Wave-length, 228.8nm EDL, Cd (6 W). 

Electrothermal atomisers come in many shapes and sizes, ranging from tube furnaces to metal ribbons. At present, the most popular form is the graphite tube furnace of which a number of designs are commercially available. The electrothermal devices vary markedly in their atomisation characteristics and a method suitable for one design will not necessarily work on another without some modification. 

In 1955, A. Walsh recognized this and showed how the absorption from the great preponderance of unexcited molecules could be exploited analytically.Thus, in atomic absorption spectroscopy (AAS) the light from a (usually modulated) somce emitting the spectrum of the desired analyte element is passed through a sample atomization cell (such as a flame or graphite tube furnace), a monochromator (to isolate the desired somce emission line) and finally into a detector to allow measmement of the change in somce line... 

Parris and collaborators have described a procedure utilizing a commercial atomic absorption spectrophotometer with a heated graphite tube furnace atomizer linked to a... 

Fig. 57. G raphite atomizers used in atomic spectrometry. (A) Original graphite tube furnace according to MafSmann (a) graphite tube with sampling hide (reprinted with permission from Ref. [172]), (B) carbon-rod atomizer system according to West (a) support (b) clamps (cooled) (c) graphite rod or cup (reprinted with permission from Ref. [175]).

Apart from graphite tube furnaces, both cups and filaments are used as atomizers in electrothermal AAS [271]. The models originally proposed by L vov et al. [171] and by Massmann [172] were described in Section 3.4. In the case of the latter, which is most widely used, the optical beam is led centrally through the graphite tube, which is closed at both ends with quartz viewing ports mounted in the cooled tube holders. Sample aliquots are introduced with the aid of a micropipette or a computer controlled dispenser through a sampling hole in the middle of the tube. 

Grgic, I. and Hudnik, V. (1989) Behaviour of mercury complexes in a graphite tube furnace for atomic absorption spectrometry. Anal. Chim. Acta, 226, 203-211. 

Table A3 Sensitivity (1% Absorption) in the Graphite Tube Furnace (HGA-70)...

Related to the carbon rod atomizer is the heated graphite tube furnace atomizer. Here, the sample is injected into the center of a graphite tube, which is resistively heated. Welz (W1) reported the determination of blood lead with such a system in which the sample is dried (20 seconds), ashed, and atomized by stepwise increase in the temperature. The precision was poor, though, being 5-10 /xg/100 ml. Norval and Butler (N3) described a graphite tube system for use on any number of atomic... 

As cone. Standard calibration, graphite tube furnace-AAS... 

Element Graphite tube furnace (100 pi measuring solution) Flame... 

Examples of relative identification limits (in pg/1) which can be achieved with the graphite tube furnace and flame techniques. The values for the graphite tube furnace technique relate to a sample volume of 100 pi. 

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