Analytical Quality Control

No matter how technically advanced or how modern the equipment and proce-dures used to determine levels of selenium, or any other element, in biological samples may be, the quality of the data generated must always be checked by a robust quality assurance programme. Knowledge of the accuracy of its data is the foundation of a laboratory’s quality control (Alvarez, 1984).

In addition to the standard techniques to ensure the quality of laboratory work and to keep to a minimum the potential for accidental loss or contamination, it is essential that analytical procedures be validated and results checked against appropriate CRMs. They are powerful tools for instrument calibration, validation of analytical procedures and achieving reliability, and they play a key role in qual-ity control and/or qualqual-ity assurance (QC/QA). The importance of having appro-priate reference standards has been underlined in a report presented to BERM, the international symposium on biological and environmental reference materials (Roelandts, 1998).

Until recently, reference materials for selenium, of appropriate concentration ranges and in different matrices, were not readily available. That situation no longer exists, at least for total concentrations, though not for individual chemical species of the element. CRMs can be obtained from a number of international ref-erence centers and agencies, such as the Institute for Refref-erence Materials and Measurements (IRMM) of the European Community, formerly known as the Bureau Communautaire des Références (BCR), the National Institute of Stan-dards and Technology (NIST) in the USA, and the International Atomic Energy Agency (IAEA) in Vienna. Table 1.2 lists a number of standards, certified for total selenium content, available from IRRM.

References

Abu-Samara, A., Morris, J.S., and Koirtyohann, S.R., 1975, Wet ashing of some biologi-cal samples in a microwave oven, Anal. Chem. 47, 1475–1477.

Alfthan, G. and Nève, J., 1996, Reference values for serum selenium in various areas—

evaluated according to the TRACY protocol, J. Trace Elem. Med. Biol. 10, 77–87.

Alt, F. and Messerschmidt, J., 1988, Selenium, in: McKenzie, H.A. and Smythe, L.E.

(eds), Quantitative Trace Analysis of Biological Materials, Elsevier, Amsterdam, p. 487.

Alvarez, R., 1984, NBS Standard Reference Materials for food analysis, in: Steward, K.K. and Whitaker, J.R. (eds), Modern Methods of Food Analysis, Avi, Westport, CT, pp. 35–40.

Amaro, M.A., Moreno, R., and Zurera, C., 1998, Nutritional estimation of changes in min-eral content during storage of white asparagus, J. Food Qual. 21, 445–458.

Bapu, S.P., 1975, Trace elements in fuel, in: Advances in Chemistry, Series 141, American Chemical Society, Washington, DC, pp. 121–147.

Berg, T. and Larsen, E.H., 1999, Speciation and legislation—where we are today and what do we need for tomorrow? Fresenius J. Anal. Chem. 363, 431–434.

TABLE1.2 Reference materials for total selenium

Material Selenium concentration Reference code

Skim-milk powder

(Spiked) (127 µg/kg)^a BCR-150

Bovine muscle 183 ± 12 µg/kg BCR-184

Bovine liver 1680 ± 140 µg/kg BCR-185R

Pig kidney 10300 ± 500 µg/kg BCR-186

Cod muscle 1.63 ± 0.07 mg/kg BCR-422

Source: Data from IRMM: Certified Reference Materials 2005. http://www.irmm.jrc.be.

aValues in brackets are not certified.

Berzelius, J.J., 1818, Lettre de M. Berzelius à M. Berthollet sur deux métaux nouveaux, Annales de Chimie et de Physique, Série 2, 7, 199–202.

Connolly, C.D., Power, R.F., and Hynes, M.J., 2004, Validation of method for total sele-nium determination in yeast by flame atomic absorption spectrometry, Biol. Trace Elem.

Res. 100, 87–93.

Crews, H.M., 1997, The analyst’s viewpoint with special reference to selenium, Nutr. Food Sci. 6, 221–228.

Crews, H.M., 1998, Speciation of trace elements in foods, with special reference to sele-nium: is it necessary? Spectrochim. Acta, Part B, 53, 213–219.

Crews, H.M., 2001, Use of stable isotopes of selenium to investigate selenium status, in:

Lowe, N. and Jackson, M. (eds), Advances in Isotope Methods for the Analysis of Trace Elements in Man, CRC Press, Boca Raton, FL, pp. 130–150.

Crews, H.M., Luten, J.B., and McGaw, B.A., 1996, Inductively coupled plasma-mass spectrometry, in: Mellon, F.A. and Sandström, B. (eds), Stable Isotopes in Human Nutrition: Inorganic Nutrient Metabolism, Academic Press, London, pp. 37–52.

Crews, H.M., Baxter, M.J., Lewis, D.J., et al., 1997, Multi-element and isotope ratio determination in foods and clinical samples using inductively coupled plasma-mass spectrometry, in: Fischer, P.W.P., L’Abbé, M.R., Cockell, K.A., and Gibson, R.S.

(eds), Trace Elements in Man and Animals 9, NRC Research Press, Ottawa, Canada, pp. 88–93.

Crombie, A.C., 1959, Medieval and Early Modern Science, Vol. 1, Doubleday, New York, pp. 137 and 230.

Crystal, R.G., 1973, Elemental selenium: structure and properties, in: Klayman, D.L. and Gunther, W.H.H. (eds), Organic Selenium Compounds: their Chemistry and Biology, Wiley, New York, pp. 107–167.

Cumming, F.J., Fardy, J.J., and Florence, T.M., 1992, Selenium and human lactation in Australia: milk and blood levels in lactating women, and selenium intakes of their breast-fed infants, Acta Paediatr. 81, 292–295.

Elkin, E.M., 1980, Selenium and selenium compounds, in: Kirk-Othmer Encyclopedia of Chemical Technology, 3rd edn., Wiley, New York, pp. 575–601.

Encinar, J.R., ´Sliwka-Kaszy ´nska, M.M., Polatajko, M.M., et al., 2003, Methodological advances for selenium analysis in yeast, Anal. Chim. Acta 500, 171–183.

Fairweather-Tait, S.J., 1997, Bioavailability of selenium, Eur. J. Clin. Nutr. 51, S20–S23.

Fleming, G.A., 1962, Selenium in Irish soils and plants, Soil Sci. 94, 28–35.

Frost, D.V., 1972, Two faces of selenium—can selenophobia be cured? in: Hemphill, D.

(ed), CRC Critical Reviews in Toxicology, CRC Press, Boca Raton, FL, pp. 467–514.

Greenwood, N.N. and Earnshaw, A., 1984, Chemistry of the Elements, Pergamon Press, Oxford, pp. 882–899.

Hansson, L., Pettersson, J., and Olin, A, 1987, A comparison of two digestion procedures for the determination of selenium in biological materials, Talanta 34, 829–833.

Hoefer, F., 1842, Histoire de la Chimie, Vol. 1, p. 389, cited in, Mellor, J.W., 1934, A Comprehensive Treatise on Inorganic and Theoretical Chemistry, Vol. x, Longmans Green, London, pp. 693–696.

Howard, J.H., 1971, Control of geochemical behavior of selenium in natural waters by adsorption on hydrous ferric oxides, in: Hemphill, D.D. (ed), Trace Substances in Environmental Health, University of Missouri Press, Columbia, MO, p. 485.

Hurd, D.L. and Kipling, J.J., 1964, Origins and Growth of Physical Science, Part 2, Penguin Books, Harmondsworth.

Jones, G.B., Buckley, R.A., and Chandler, C.S., 1975, The volatility of chromium from brewer’s yeast during assay, Anal. Chim. Acta 80, 389–392.

Klayman, D.L. and Gunther, W.H.H. (eds), 1973, Organic Selenium Compounds: their Chemistry and Biology, Wiley, New York.

Knott, S.G. and McCray, C.W.R., 1959, Two naturally occurring outbreaks of selenosis in Queensland, Aust. Vet. J. 35, 161–165.

Kumpulainen, J., 1990, Summary of new analytical techniques and general discussion, in:

Tomita, H. (ed), Trace Elements in Clinical Medicine, Springer, Tokyo, pp. 541–546.

Kumpulainen, J., Raittila, A., Lehto, J., and Koivistoinen, P., 1983, Electrothermal atomic absorption spectrometric determination of selenium in foods and diets, JAOAC. 66, 1129–1135.

Lachica, M., 1990, Use of microwave oven for the determination of mineral elements in biological materials, Analusis 18, 331–333.

Levander, O.A., 1976, Selective aspects of the comparative metabolism and biochemistry of selenium and sulfur, in: Prasad, A.S. (ed.), Trace Elements in Human Health and Disease, Vol. 2, Academic Press, New York, pp. 135–163.

Lobinski, R., Edmonds, J.S., Suzuki, K.T., and Uden, P.C., 2000, Species-selective deter-mination of selenium compounds in biological materials, Pure Appl. Chem. 72, 447–461.

Mizutani, T., Kishimoto, M., and Yamada, K., 1992, Selenium levels in Chinese plants relating to the travels of Marco Polo, in: Fifth Int Symp. Se Biol. Med, Abstracts. July 20–23 1992, Vanderbilt University, Nashville, TN, p. 143.

National Research Council, 1971, Selenium in Nutrition, National Academy Press, Washington, DC.

Neas, E.D. and Collins, M.J., 1985, Microwave heating: theoretical concepts and equipment design, in: Kingston, H.M. and Jassie, L.B. (eds), Introduction to Microwave Sample Preparation: Theory and Practice, ACS Professional Book, American Chemical Society, Washington, DC, pp. 23–40.

Oldfield, J.M., 1990, Selenium: its Uses in Agriculture, Nutrition and Health and the Environment, Selenium-Tellurium Development Association, Grimbergen, Belgium.

Oldfield, J.E., 1999, Selenium World Atlas, Selenium-Tellurium Development Association, Grimbergen, Belgium.

Oles, P.J. and Graham, W.M., 1991, Microwave acid digestion of various food matrices for nutrient determination by atomic absorption spectrophotometry, JAOAC 74, 812–814.

Polo, M., 1967, The Travels of Marco Polo, translated by Marsden, E.W., revised by Wright, T., Everyman’s Library, Dent, London, pp. 110–111.

Ray, S.J., Andrade, F., Gamez, G., et al., 2004, Plasma-source mass spectrometry for spe-ciation analysis: state of the art, J. Chromatogr. 1050, 3–23.

Roelandts, I., 1998, Seventh International Symposium on Biological and Environmental Reference Materials (BERM-7), Antwerp, Belgium, 21–25 April 1997, Spectrochim.

Acta, Part B, 53, 1365–1368.

Selenium Tellurium Development Association, 1993, Information on the Handling and Storage of Selenium, Selenium Tellurium Development Association, Grimbergen, Belgium.

Shriver, D.F. and Atkins, P.W. 1999, Inorganic Chemistry, 3rd edn., Oxford University Press, Oxford.

Slejkovec, Z., Van Elteren, J.T., Woroniecka, U.D., et al., 2000, Preliminary study of the determination of selenium compounds in some selenium-accumulating mushrooms, Biol. Trace Elem. Res. 75, 139–155.

Tinggi, U. and Craven, G., 1996, Determination of total mercury in biological materials by cold vapor atomic absorption spectrometry after microwave digestion, Microchem.

J. 54, 168–173.

Tinggi, U., Reilly, C., Hahn, S., and Capra, M., 1992a, Comparison of wet digestion procedures for the determination of cadmium and lead in marine biological tissues by Zeeman graphite furnace atomic absorption spectrophotometry, Sci. Total Environ. 125, 15–23.

Tinggi, U., Reilly, C., and Patterson, C.M., 1992b, Determination of selenium in foodstuffs using spectrofluorimetry and hydride generation atomic absorption spectrometry, J. Food Comp. Anal. 5, 269–280.

Trelase, S.F., 1942, Bad earth, Sci. Monthly 54, 12–28.

University of Missouri Research Reactor Center, 2004, Inductively Coupled Mass Spectrometry, http://www.missouri.edu/~murrwww/pages/ac_icpms1.shtml.

Ursini, R. and Bindoli, A., 1987, The role of selenium peroxidases in the protection against oxidative damage of membranes, Chem. Phys. Lipids 44, 255–276.

van der Krogt, P., 2004, Elementology and Elements Multidictionary, http://vanderkrogt.

net/elements/elem/se.html.

Versieck, J. and Cornelis, R., 1989, Trace Elements in Human Plasma or Serum, CRC Press, Boca Raton, FL, p. 76.

Watkinson, J.H. and Davies, E.B., 1967, Uptake of native and applied selenium by pasture plants III. Uptake of selenium from various carriers. NZ J. Agric. Res. 10, 116–121.

World Health Organization, 1987, Environmental Health Criteria 58: Selenium, WHO, Geneva.

Yang, G., Wang, S., Zhou, R., and Sun, S., 1983, Endemic selenium toxicity of humans in China, Am. J. Clin. Nutr. 37, 872–881.

Ysart, G., Miller, P., Crews, H., et al., 1999, Dietary exposure estimates of 30 elements from the UK Total Diet Study, Food Add. Contam. 16, 391–403.

Zingaro, R.A. and Cooper, R., 1974, Selenium, Van Nostrand Reinhold, New York, pp. 788–807.

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