ETAAS atomizers

ETAAS. In ETAAS atomization takes place in an electrothermal atomizer which is heated to the appropriate temperature programme. The detection limits of the method are about two or three orders of magnitude better than FAAS. It is applicable to about 40 elements but generally for about 20 elements detection limits at the ng and pg level can be reached. Commensurable or better sensitivities have only INAA, ICP-MS and stripping voltammetry. Therefore ETAAS is widely used for environmental analysis. However the method suffers from serious interferences leading to systematic errors due to thermochemical processes in the atomizer. Background absorption is also a potential source for systematic errors. Spectral interferences are additive and cannot be corrected by the popular standard addition method. ETAAS is also not free of memory effects for refractory elements. 

Fig Recordings of ETAAS atomization signals for lead in water samples using on-line sorbent extraction separation and preconcentration, (a) Blank (b) 0.100 fig P Pb standard (c)... 

A general overview of atomic spectrometric techniques, including atomic absorption spectroscopy (FAAS and ETAAS), atomic emission spectrometry (ICP-OES), and mass spectrometry (ICP-MS), for the determination of uranium was published (Santos et al. 2010). The advantages and limitations of each technique were discussed and compared and the complexity and costs were also considered. In addition, use of preconcentration and separation to improve performance was also described. 

S. Carballo-Paradelo, R. M. Soto-Ferreiro, S. Amor-Pastoriza, A. Carlosena-Zubieta, E. Fernandez-Femandez, S. Muniategui-Lorenzo, P. Lopez-Mahia and D. Prada-Rodriguez, Direct determination of V, Ni, and Co in emulsified fuel oil samples by electrothermal atomic absorption spectrometry (ETAAS), Atom. Spectrosc., 2009, 30(4), 129-138. 

Miscellaneous. Trace analyses have been performed for a variety of other materials. Table 9 Hsts some uses of electrothermal atomic absorption spectrometry (etaas) for determination of trace amounts of elements in a variety of matrices. The appHcations of icp /ms to geological and biological materials include the following (165) ... 

The development of methods using sorbents modified with analytical reagents that enable analytical signal measuring directly on the surface by solid-phase spectrometry, visually or by electrothermic atomic absorption spectroscopy (ETAAS) after elution is now a subject of growing interest. 

Electrode System Etaa/V VS. SHE Atomic density/cm-2 Method References... 

Method abbreviations D-AT-FAAS (derivative flame AAS with atom trapping), ETAAS (electrothermal AAS), GC (gas chromatography), HGAAS (hydride generation AAS), HR-ICP-MS (high resolution inductively coupled plasma mass spectrometry), ICP-AES (inductively coupled plasma atomic emission spectrometry), ICP-MS (inductively coupled plasma mass spectrometry), TXRF (total reflection X-ray fluorescence spectrometry), Q-ICP-MS (quadrapole inductively coupled plasma mass spectrometry)... 

Multi-element AAS has been reviewed [112], as well as ETAAS [104] and instrumental aspects of GFAAS [113]. Various monographs on analytical atomic absorption spectrometry are available [52,96,114,115], and on GFAAS [116] and ETAAS [117] more in particular. 

EDI-CI Electric discharge-induced chemical ionisation ETAAS, ET-AAS Electrothermal (atomisation) atomic absorption spectrometry... 

A comparative study was carried out of ashing and atomization techniques in the GFAAS method for direct determination of Pb in bovine liver45. Bismuth nitrate was proposed as matrix modifier for ETAAS determination of Pb in animal tissues LOD 0.9 pg/L46. 

Analysis. The colorimetric method for In is capable of a detection limit of 20 ppb. Indium or an In compound in the flame gives an indigo blue color (451.1 nm). This photon line allows for the spectrophotometric determination ofinby AAS (atomic absorption flame spectroscopy). The method is sensitive to about 300 ppb. With ETAAS, this limit drops to 10 ppb, as it does with ICPAES. ICPMS drops the limit to 0.01 ppb. Alizarin detects In, as well as Al, but the reaction with Al can be masked by addition of F to a spot test. The limit of detection is about 1 ppm. 

Analysis. Atomic absorption, emission, and mass spectrographic separation are the most sensitive methods for the analysis of Si. Electrothermal atomization-atomic absorption spectroscopy ETAAS has a sensitivity of 10 ppb, ICPAES 1 ppb, and ICPMS 10 ppb. Colorimetric agents permit spectrometric analysis down to about 10 ppb. 

About 70 elements of the Periodic Table can be determined by optical techniques of atomic spectrometry. AAS techniques are basically considered as single element (particularly so for ETAAS, where the lamp and the atomisation conditions have, as a rule, to be selected individually for each element). This feature determines that the sample throughput in AAS (especially with ETAAS) is comparatively low. 

M. J. Cal-Prieto, M. Felipe-Sotelo, A. Carlosena, J. M. Andrade, P. Lopez-Mahia, S. Muniategui and D. Prada, Slurry sampling for direct analysis of solid materials by electrothermal atomic absorption spectrometry (ETAAS). A literature review from 1990 to 2000, Talanta, 56, 2002, 1-51. 

I. Arambarri, R. Garcia and E. Millan, Application of experimental design in a method for screening sediments for global determination of organic tin by electrothermal atomic absorption spectrometry (ETAAS), Fresenius J. Anal. Chem., 371(7), 2001, 955-960. 

S. Ch. Nielsen, S. Sturup, H. Spliid and E. H. Hansen, Selective flow injection analysis of ultra-trace amounts of Cr(VI), preconcentration of it by solvent extraction and determination by electrothermal atomic absorption spectrometry (ETAAS), Talanta, 49(5), 1999, 1027-1044. 

As an example, Figure 4.9 shows the overall set of atomic peaks of the calibration samples stacked on the same plot. This corresponds to a study where antimony had to be determined by ETAAS in natural waters (drinking water, wells, springs, etc.) [12]. An extensive study of potential interferents [21] revealed that several ions may interfere in the atomisation process. A PLS multivariate study was carried out as an alternative to classical approaches and standard solutions were prepared with various concentration of Sb and the... 

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