Atomic absorption detection

Atomic Absorption Detection Limits for Selected Elements... 

A flow-injection system with electrochemical hydride generation and atomic absorption detection for the determination of arsenic is described. This technique has been developed in order to avoid the use sodium tetrahydroborate, which is capable of introducing contamination. The sodium tetrahydroborate (NaBH ) - acid reduction technique has been widely used for hydride generation (HG) in atomic spectrometric analyses. However, this technique has certain disadvantages. The NaBH is capable of introducing contamination, is expensive and the aqueous solution is unstable and has to be prepared freshly each working day. In addition, the process is sensitive to interferences from coexisting ions. 

Valkirs et al. [105] have conducted an interlaboratory comparison or determinations of di- and tributyltin species in marine and estuarine waters using two methods, namely hydride generation with atomic absorption detection and gas chromatography with flame photometric detection. Good agreement was obtained between the results of the two methods. Studies on the effect of storing frozen samples prior to analysis showed that samples could be stored in polycarbonate containers at - 20 °C for 2 - 3 months without significant loss of tributyltin. 

Lawrence, J.F., Michalik, P., Tam, G. and Conacher, H.B.S. (1986). Identification of arsenobetain and arsenocholine in Canadian fish and shellfish by high-performance liquid chromatography with atomic absorption detection and confirmation by fast atom bombardment mass spectrometry, J. Agric. Food Chem., 34, 315-319. 

HasweU and Barclay [3] have described a microwave system coupled to an atomic absorption detection system for the analysis of sludges and soils. A major constraint at the present time is that the preferred operation of these types of systems is for sample matrices to be closely matched. A widely varying sample, which exhibits different heating characteristics, wiU either show up as an invaHd result or the time required to cope with this procedure for aU the samples wiU greatly extend the on-Hne analyses time scales. As more of these instrumental systems become Hnked to laboratory information management systems, it wiU become feasible to interact between the control database and the instrumentation so that each sample is treated in an appropriate manner and the optimum time frame is selected for each sample type. When new samples are analysed, the steps could be monitored so that the required time scales are obtained and then stored for future reference. 

Determination of Inorganic and Organic Arsenic Species by Ion Chromatography Using an Atomic Absorption Detection System , Ricci, G. Colovos, G. Hester, N. Shepard, L Anal. Chem., accepted for publication 1980. 

P Vinas, N Campillo, I Lopez-Garcfa, M Hemandez-Cordoba. Identification of vitamin B,2 analogues by liquid chromatography with electrothermal atomic absorption detection. Chromatographia 42 566-570, 1996. 

Commonly used techniques for this purpose are chromatography and hyphenated methods, mostly coupled with element-specific detection, for example, GC-AED,221 GC coupled with atomic absorption detection (GC-AAS),222 or ICP-MS. The last mentioned provides superior sensitivity as well as the possibility of using isotopically labeled standards for quantification and quality control.223... 

W. Holak, Analysis of mercury-containing drugs by HPLC with atomic absorption detection, J. Liquid Chromatogr., 5 73 (1985). 

The gas chromatograph is equipped with an electron capture detector or with an atomic absorption detection system using samples of 1-50 ml. 

Thermally-released Hg is determined by means of a simple flameless atomic absorption detection system (Fig. 13-2). This has a sensitivity of 0.1 ng Hg and a limit of detection of 0.01 ng Hg. In the temperature range 120-150"C adsorbed Hg (subsequently termed Hg J, comprising Hg, HgCh, Hg CF and any Hg , is released and measured. When the temperature is raised to 800"C, all forms of Hg (Hg,) are released. The determination of Hg as these two groups of compounds aids the understanding of Hg dispersion and hence exploration. 

The determination of Se03- and SeOc in water with graphite furnace atomic absorption detection was investigated by Chakraborti et al. [22]. Some interference by Cl" and F was reported. DCPAE detection was used by Urasa and Ferede [23]. Results were 1000 times more sensitive than conductivity detection. One of the advantages of atomic emission detection was described in this work. Identical molar sensitivity was obtained for both species. Mehra et al. [24] developed a novel singlecolumn IC method to determine selenium species in seleniferous soil samples. The separation took about 14 minutes and there were no reported interferences. 

For measuring at low concentrations, the derivatisation of the extracted organotin compound with sodium tetraethylborate is an established procedure to make a more sensitive gas chromatographic analysis possible. Derivatisation can be combined with the extraction as prescribed in the German method but can also be carried out after the extraction. Selective detection is possible using GC-MS. For organo-metallic compounds atomic emission or atomic absorption detection is not only very sensitive, but very selective. The steps necessary for the chromatographic separation and detection are described in ISO/CD 17353 (2001). Application of this well-described method for soil samples does not mean that the difficulties with the extraction have been overcome. 

Table 7.7. Atomic absorption detection limits and sensitivities with a conventional flame atomizer...

L. Nord and B. Karlberg, Sample Preconcentration by Continuous Flow Extraction with a Flow Injection Atomic Absorption Detection System. Anal. Chim. Acta, 145 (1983) 151. 

B. F. Rocks, R. A. Sherwood, Z. J. Turner, and C. Riley, Serum Iron and Total Iron-Binding Capacity Determination by Flow Injection Analysis with Atomic Absorption Detection. Ann. Clin. Biochem., 20 (1983) 72. 

Schmidt. P.F. (1984). Localization of trace elements with the laser microprobe mass analyzer (LAMMA), Trace Elements in Medicine, 1,13-20 Sherwood. R.A., Rocks, B.F., and Riley, C. (1984). The use of flow-injection analysis (FIA) with atomic absorption detection for the determination of clinically relevant elements. Paper presented at 2nd BNAAS Symposium, Leeds, July 1984 Triebig, G., and Schaller, K.H. (1984). Copper, in Alessio, L, Berlin, A., Boni, M., Roi, R., Biological indicators for the assessment of human exposure to industrial chemicals, p. 57-62, EUR 8903 EN, Commission of the European Communities Van der Vyner, F.L, Verbreuken, A.H., Van Grieken, R.E., and DeBroe, M.E. (1985) Laser microprobe mass analysis A tool for evaluating histochemical staining of trace elements, Clin. Chem., 31. 351... 

Table I. Atomic Absorption Detection Limits (Continued) ...

Dichromate oxidation via microwave-assisted digestion FAAS 25-5000 mg Retention of the excess of dichromate on an anionic exchange column prior atomic absorption detection... 

A comparison of the detection limits for the rare earth elements in flame atomic emission and absorption spectrometry (table 37D.3 in section 2.2.5) allows certain conclusions to be made. The fuel-rich oxyacetylene and nitrous oxide-acetylene flames are very effective in producing free atoms of these elements and are the flames of choice for both atomic emission and absorption analysis. The emission detection limits are equal to or better than those obtained by absorption techniques, and thus flame atomic emission methods are generally superior. Future improvements in hollow cathode discharge tubes (or development of other primary sources) may lower the atomic absorption detection limits and thereby make the two techniques more complementary. However, Kinnunen and Lindsjo (1967) have emphasized that locating the proper rare earth ab-... 

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