Quality assurance, trace element

Quevauviller Ph, Herzig R. and Muntau H (1996b) Certified reference material of lichen (CRM 482) for the quality control of trace element biomonitoring. Sci Total Environ 187 143-152 Quevauviller Ph, Lachica M., Barahona E, Rauret G, Ure A, Gomez A, and Muntau H (1997) The certification of the EDTA-extractable contents (mass fractions) of Cd, Cr, Ni, Pb, and Zn and of the DTPA-extractable contents (mass fractions) of Cd and Ni in calcareous soil by the extraction procedures given CRM 600. EUR Report 17555 Quevauviller Ph. Maier EA, and Griepink B, eds. (1995) Quality Assurance for Environmental Analysis. Elsevier. Amsterdam. 

Wise SA, Schantz MM, Poster DL, Lopez de Alda MJ, and Sander LC (2000) Standard reference materials for the determination of trace organic constituents in environmental samples. In Barcelo D, ed. Sample Handling and Trace Analysis of Pollutants Techniques, Applications and Quality Assurance, pp 649-687. Elsevier Science Publishers, Amsterdam, The Netherlands. Yoshinaga Y, Morita M, and Okamoto K (1997) New human hair certified reference material for methylmercury and trace elements. Fresenius J Anal Chem 357 279-283. 

Trends in element analysis are multi-element (survey) analysis, lower concentration levels, micro/local element analysis and speciation (coupling with chromatography). An overview of the determination of elements in polymeric materials is available [7], Reviews on sample preparation for trace analysis are given in refs [8-10]. Quality assurance of analytical data in routine elemental analysis has been discussed [11], Organic analysis is obviously much more requested in relation to polymer/additive matrices than elemental analysis. 

Multi-element trace analysis is an important prerequisite for the quality assurance of foodstuffs with respect to the characterization of non-essential, toxic and essential (nutrient) elements as pollutions or as mineral elements relevant to health. Contamination with heavy metals such as Cd, Pb or Hg has become a serious problem with increasing environmental (artificial) contamination e.g., due to industrial pollution. The increasing use of inorganic mass spectrometric techniques (especially of ICP-MS) in the analysis of foodstuffs for multi-element analysis of trace elements or the detection of selected elements and species at a low concentration level has resulted from advances in very sensitive and quantitative measurements of metals, metalloids and several non-metals, including their speciation. 

We have employed two multi-elemental techniques (INAA and ICP-AES) to determine sulphur, halogens and 14 other trace elements in urban summer rainfall. Quality control was assured using NBS reference materials. The overall accuracy and precision of these two methods makes possible the routine analysis of many environmentally important trace elements in acid rain related investigations. Enrichment factor calculations showed that several elements including S, Cu, Zn and Cr were abnormally enriched in the urban atmosphere. A comparison of three separate sites showed a strong gradient of metal deposition from the industrial to the outlaying areas. 

Versieck, J. Collection and manipulation of samples for trace element analysis Quality assurance considerations. In Quality assurance in biomedical neutron activation analysis. IAEA-TECDOC-323. IAEA, Vienna, pp. 71-82 (1984)... 

Van Dael, P. Trace element speciation in food a tool to assure food safety and nutritional quality. In Ebdon, L., Pitts, L., Comelis, R., Crews, H., Donard, O.F.X., Quevauviller, P. (eds.) Trace Element Speciation for Environment, Food and Health, pp. 233-240. RSC, Cambridge (2001)... 

Volume 14 Analystical Applications of Circular Dichroism edited by N. Purdie and H.. Brittain Volume 15 Trace Element Analysis in Biological Specimens edited by R.F.M. Herberand M. Stoeppler Volume 16 Flow-through (Bio) Chemical Sensors by M.Valcarcel and M.D. Luque de Castro Volume 17 Quality Assurance for Environmental Analysis edited by Ph. Quevauviller, E.A. Maier and B. Griepink Volume 18 Instrumental Methods in Food Analysis edited by J.R.J. Pare and N.M.R. Belanger... 

BOX 30-1 Organizations Providing Proficiency Testing and Quality Assurance Programs for Trace Element Testing Laboratories... 

Brown, S.S. (1991) Quality assurance achievements, problems and prospects. In Aitio, A., Aaro, A., Jarvisalo, J. and Vainio, H. (Eds.) Trace Elements In Health and Disease, Royal Society of Chemistry, London p. 37. 

Improved methods of analytical quality assurance, and their consistent application by analysts everywhere, would thus appear to be urgent requirements in trace element research. To this end, all aspects of quality assurance, both internal and external, need careful attention. In this work, reference materials perform an essential function. Indeed quality assurance without reference materials is largely inconceivable. 

It is partly reassuring that the quality assurance of trace element analysis is now attracting increased attention, which is also demonstrated by a series of international symposia on biological and environmental reference materials (Wolf. 1985 Wolf and Stoeppler, 1987,1988, 1990 Wagstaffe et al,. 1993). Therefore, reference materials, such as those considered in this chapter, are being used by more and more by analysts. This is... 

Keith, L.H. et al. (1983). Principles of environmental analysis, Anal. Chem. 55, 2210 Klich, H. and Walker, R, (1993). COMAR - The international database for certified reference materials, Fresenius J. Anal. Chem. 24S, 104 Kurfurst, U., Pauwels, J., Grobecker, K.-H., Stoeppler, M., Muntau, H. (1993). Micro-heterogeneity of trace elements in reference materials - determination and statistical evaluation, Fresenius J. Anal. Chem. 345.112 Parr, R.M. (1984). Quality assurance of trace element analysis, in Health Effects and Interactions of Essential and Toxic Elements (Proc. Symp. Lund, Sweden, June 1983) Nutrition Research, special supplement... 

Figure 3 Illustrates the problem faced by the IAEA in the broader context of their trace element laboratory intercomparison program. These data show the reported results of 16 laboratories for measurements of arsenic in the horse kidney intercomparison sample (H-8), based on various versions of atomic absorption spectrometry, optical emission spectrometry, neutron activation analysis, and Induced X-ray emission analysis. The objective of the horse kidney intercomparison was to assess (and refine) analytical methods for the determination of essential and toxic trace elements in this surrogate for human kidney (2). Kidney, as the main target organ which accumulates toxic elements, was of special Interest with respect to cadmium. Horse kidney, which contains similar levels of cadmium to the human kidney cortex, was selected for the development and maintenance of methods having a demonstrated level of quality to assure reliable biological monitoring of this element. Participants were Invited to analyze some 24 additional trace elements, however.

Mercury is a unique metal. Its oceanic background concentration (Hgx) is very low (< 1 ng/L see also Table 12-1). The risks of rapid changes in speciation, losses and contamination of samples by contact with laboratory air, materials and reagents are high. In contrast to other trace elements, seawater reference materials certified for mercury concentration are not yet available. The quality assurance with regard to accuracy of data is further hampered by the fact that most laboratories, due to the lack of alternative methods, follow almost the same analytical approach. 

In addition to drinking water. Method 200.8 can also be used for trace elements in wastewater under the National Pollutant Discharge Elimination System (NPDES). It has had general approval since 1995, but full acceptance varies on a regional basis, which means that each laboratory must apply for an ATP (Alternate Test Procedure) to their local EPA Quality Assurance Officer. In addition, since January 2000, Method 200.8 can also be used under NPDES rules for the analysis of wastewater from industrial incinerators. Other Office of Water ICP-MS-related methodology include the following ... 

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