Ultra-trace Elements

Laser ablation ICP-MS (LA-ICP-MS) was established in the early 1990s as a potential routine tool for the measurement of trace and ultra-trace elements in silicate systems for geology. Early studies (Perkins et al. 1993) used sample preparation techniques identical to that used to prepare rock samples for WDXRF, i.e., either a pressed powder disk or a glass bead fusion method (see Appendix VIII). Such studies concluded that LA-ICP-MS had the potential to surpass XRF in terms of the limits of detection achieved and INAA in terms of the speed of analysis (Perkins et al. 1993 481). It has long been recognized that the main limit on the quantitative performance of LA-ICP-MS is the homogeneity at the trace and ultra-trace level of the solid calibration standards available. Subsequent work (e.g., Hollecher and Ruiz 1995, Norman et al. 1996) has demonstrated that some of the international... 

Perkins, W. T., Pearce, N. J. G., and Jeffries, T. E. (1993). Laser ablation inductively coupled plasma mass-spectrometry - a new technique for the determination of trace and ultra-trace elements in silicates. Geochimica et Cosmochimica Acta 57 475—482. 

Bensimon M, Bourquin J, Parriaux A (2000) Determination of ultra-trace elements in snow samples by inductively-coupled plasma source sector field mass spectrometry using ultrasonic nebulization. J Anal Atom Spectrom 15 731-734... 

J.-P. Perez-Trujillo, M. Barbaste and B. Medina, Chemometric study of bottled wines with denomination of origin from the Canary Islands (Spain) based on ultra-trace elemental content determined by ICP-MS, Anal. Lett., 36(3), 2003, 679-697. 

The detection limits obtained by flame and graphite furnace AAS and the concentration levels of the elements in seawater are summarized in Table 2. In general, graphite furnace AAS provides better sensitivities for many elements than the flame technique. Even so, AAS sensitivity is insufficient for the direct determination of most ultra-trace elements. Furthermore, concentrated salts and undissolved particulates cause severe interferences with the determination of trace elements by AAS. Therefore, it is necessary to concentrate the analytes before the determination, and, if possible, to separate the analytes from dissolved major constituents and particulates. Solvent extraction, coprecipitation and ion-exchange techniques are the most widely used techniques for the preconcentration of seawater. In the following sections, these techniques will be reviewed. It should be noted here that the efficiencies of the recovery of the analytes as well as the contamination from reagents and solvents must be carefully examined when the preconcentration techniques are applied. Chakrabarti et al. [10] have summarized the work on the application of preconcentration techniques to marine analysis by AAS. Hence, only some representative applications will be introduced hereafter. 

P. Benes, V. Majer, Trace Chemistry of Aqueous Solutions, Elsevier, Amsterdam, 1980 R. Guillaumont, P. Chevallier, J. P. Adloff, Identification of Oxidation States of Ultra-trace Elements by Radiation Detection, Radiochim. Acta 40, 191 (1987)... 

Mertz, W. Chromium, an ultra trace element. Chem. Scripta 1983 21 71-83... 

Bauer, K.H., Eschnauer, H.R. and Gortges, S. (2001) Indicator elements in wine analysis. The ultra-trace elements Beryllium and Zirconium. In Abstract book 2nd Symp. In Vino Analytica Scientia 2001 , p. 30, Ecole Europeenne de Chemie Analytique (Ed.). 

NAA is widely used in many different fields of sciences. Applications include environmental studies to characterize pollutants, semiconductor materials analysis to measure ultra trace-element impurities, archaeological studies of the distribution of the chemical elements and fossil materials, forensic studies as a non-destructive method (suspect chemical agents, see Figure 17.9), pharmaceutical materials analysis to measure ultra-trace element impurities, etc. Unfortunately, facilities for using this method do not exist everywhere. Otherwise, the sample becomes slightly radioactive, requiring the sample to be quarantined until its activity reaches a state similar to which it was before the NAA. 

Nutrients, macro, trace and ultra trace elements in the feed chain of mouflons and their mineral status. First part Nutrients and Macroelements. In Nahlik A and Uloth W, eds. Third International Symposium on Mouflon. pp. 225-242, Lover Print, Sopron Hungary. 

Anke M, Groppel B, Arnhold W, Langer M and Krause U (1990) The influence of the ultra trace element deficiency (Mo, Ni, As, Cd, V) on growth, reproduction performance and life expectancy. In Tomita H, ed. Trace Elements in Clinical Medicine. Spiinger-Verlag, Tokyo, pp. 361—376. 

Anke M (1991) The essentiality of ultra trace elements for reproduction and pre- and postnatal development. In Chandra RJ, ed. Trace Elements in Nutrition of Children - II, Nestle Nutrition Workshop Series, Vol 23, Nestec Ltd, Vevey Raven Press Ltd, New York pp. 119—143. 

Smith HA (1984) Cadmium. In Frieden E, ed. Biochemistry of the Essential Ultra Trace Elements. Plenum Press, New York-London, pp. 341-366. 

Ward NI (1987) The future of multi- ultra-trace- element analysis in assessing human health and disease A comparison of NAA and ICP-MS. Environ Health 20 118-123. 

Kirghgessner M and Weigand E (1985) Absorption and excretion of zinc. In Gladtke E, Heimann G, Lombeck I and Eckert 1, eds. Spurenelemente - Stoffwechsel, Ernahrung, Imbalancen, Ultra-Trace-Elemente, pp. 30-46. G. Thieme Verlag, Stuttgart-New York. 

Anke M (2003a) Arsenic in plants, soils and some foodstuffs. In Shtangeva I, ed. Trace and Ultra Trace Elements in Plant and Soil. Wit Press Southampton, U.K, in press. 

Cornells, R. and Versieck, J. (1983) Clinical reference materials certified for ultra-trace element levels utopia or far-off reality. In Brown, S.S. and Savory, J. (Eds.) Chemical Toxicology and Clinical Chemistry of Metals, Academic Press, London, p. 81. 

ICPMS can be used for both qualitative and quantitative trace and ultra trace elemental analysis of inorganics and in isotope ratio determinations. Both cations and anions can be determined. Normally, the sample is introduced in the form of a solution into the plasma, but direct analysis of gaseous or solid sample is also possible. Hence, ICP-MS has grown into a referral technique for the ultra trace analysis of REE in electronic materials, and metallurgical samples. The individual REE concentrations in natural and sea waters are so low and require preconcentration techniques prior to determination by ICP-MS. Separation in addition to preconcentration is also needed as high salt matrix of sea waters results in irreproducible results in ICP-MS analysis of individual REE. 

Dawczynski, C., U. Schaefer, M. Leiterer, and G. Jahreis. 2007. Nutritional and toxicological importance of macro, trace, and ultra-trace elements in algae food products. /. Agric. Food Chem. 55(25) 10470-10475. 

Abstract This chapter presents the basic principles of activation analysis and details its different types. Emphasis is given to instrumental neutron activation analysis and radiochemical separations for the determination of trace and ultra-trace elements. Location sensitive analysis is also included. 

Takeda, K., Ikushima, S., Okuzaki, J., Watanabe, S., Fujimoto, T., Nakahara, T. (2001) Inductively coupled plasma mass spectrometric determination of ultra-trace elements in electronic-grade water and chemicals using dulcitol. Analytica Chimica Acta, 426,105-109. 

The Perkin Elmer Elan 500 instrument is designed for routine and rapid multi-element quantitative determinations of trace and ultra-trace elements and isotopes. The Elan 500 can determine nearly all of the elements in the periodic table with exceptional sensitivity. 

Because the ohmic drop has a minimal influence on voltammetric responses, the addition of supporting electrolytes to the solutions is often unnecessary [1,2, 9,10]. This helps to avoids the contamination of samples by external chemicals when ultra-trace element analysis needs to be performed, and also leaves the chemical equilibria unaltered. Consequently, direct measurements of low-ionic strength samples or resistive media and speci-ation measurements can be performed in a straightforward manner, without any need for pretreatment [57,58]. 

---