Trace element determination

Vandecasteele, G. Block, G. B. Modern Methods for Trace Element Determination. Wiley Ghichester, England, 1994. 

The high-purity water thus produced typically has a conductance of about 0.5 x 10-6fi-1cm-1 (0.5juScm-1) and is suitable for use under the most stringent requirements. It will meet the purity required for trace-element determinations and for operations such as ion chromatography. It must however be borne in mind that such water can readily become contaminated from the vessels in which it is stored, and also by exposure to the atmosphere. For the determination of organic compounds the water should be stored in containers made of resistant glass (e.g. Pyrex), or ideally of fused silica, whereas for inorganic determinations the water is best stored in containers made from polythene or from polypropylene. 

Versieck J, Vanballenberghe L, de Kesel A, Baeck N, Steyart H, Byrne AR and Sunderman FW Jr. (1988) Certification of a second-generation biological reference material (freeze dried human serum) for trace element determinations. Anal Chim Acta 204 63-75. 

Klemm W, Baumeach G (1995) Trace element determination in contaminated sediments and soils by ultrasonic slurry sampling and Zeeman graphite furnace atomic absorption spectrometry. Fresenius J Anal Chem 353 12-15. 

Fodor, P. and Molnar, E. (1993). Honey as an environmental indicator Effect of sample preparation on trace element determination by ICP-AES. Microchim. Acta 112,113-118. 

Decomposition methods are usually classified as melt decompositions, wet decompositions (with liquid decomposing agents) and dry decompositions by combustion. Sample decomposition methods are varied, and involve open and closed systems (at low and high pressure), UV and thermal activation, low or high temperature, and use of conventional convective or microwave heating. Table 8.4 lists the main sample decomposition methods for trace-element determination. 

Conventional XRF analysis uses calibration by regression, which is quite feasible for known matrices. Both single and multi-element standards are in use, prepared for example by vacuum evaporation of elements or compounds on a thin Mylar film. Comparing the X-ray intensities of the sample with those of a standard, allows quantitative analysis. Depending on the degree of similarity between sample and standard, a small or large correction for matrix effects is required. Calibration standards and samples must be carefully prepared standards must be checked frequently because of polymer degradation from continued exposure to X-rays. For trace-element determination, a standard very close in composition to the sample is required. This may be a certified reference material or a sample analysed by a primary technique (e.g. NAA). Standard reference material for rubber samples is not commercially available. Use can also be made of an internal standard,... 

C. Vandecasteele and C.B. Block, Modem Methods for Trace Element Determination, J. Wiley Sons, Ltd, Chichester (1993). 

Charged particle activation analysis (CPAA) is based on charged particle induced nuclear reactions producing radionuclides that are identified and quantified by their characteristic decay radiation. CPAA allows trace element determination in the bulk of a solid sample as well characterization of a thin surface layer. 

Linderholm, J. and E. Lundberg (1994), Chemical characterization of various archaeological soil samples using main and trace elements determined by inductively coupled plasma atomic emission spectrometry,. Archaeol. Sci. 21, 303-314. 

Vandecasteele et al. [745] studied signal suppression in ICP-MS of beryllium, aluminium, zinc, rubidium, indium, and lead in multielement solutions, and in the presence of increasing amounts of sodium chloride (up to 9 g/1). The suppression effects were the same for all of the analyte elements under consideration, and it was therefore possible to use one particular element, 115indium, as an internal standard to correct for the suppressive matrix effect, which significantly improved experimental precision. To study the causes of matrix effect, 0.154 M solutions of ammonium chloride, sodium chloride, and caesium chloride were compared. Ammonium chloride exhibited the least suppressive effect, and caesium chloride the most. The results had implications for trace element determinations in seawater (35 g sodium chloride per litre). 

Nadkami, R.A. and W.D. Ehmann. 1970. Trace element determination in biological materials by neutron activation analysis. Pages 407-419 in D.D. Hemphill (ed.). Trace Substances in Environmental Health IV. Univ. Missouri, Columbia. 

K. G. Heumann. Isotope-dilution ICP-MS for Trace Element Determination and Speciation From a Reference Method to a Routine Method Anal. Bioanal. Chem., 378(2004) 318-329. 

F. L. King, J. Teng, and R. E. Steiner. Glow Discharge Mass Spectrometry Trace Element Determinations in Solid Samples. J. Mass Spectrom., 30(1995) 1061-1075. 

Emeleus, V.M. (1958). The technique of neutron activation analysis as applied to trace element determination in pottery and coins. Archaeometry 1 6-15. 

Hollocher, K. and Ruiz, J. (1995). Major and trace-element determinations on NIST glass standard reference material-611, material-612, material-614, and material-1834 by inductively-coupled plasma-mass spectrometry. Geostandards Newsletter 19 27-34. 

The analysis of tetramethylammonium hydroxide (TMAH) solutions manufactured by SACHEM Inc. of Cleburne, Texas, includes the determination of trace elements. These elements cause less-than-optimum performance of integrated circuit boards manufactured by SACHEM s customers that use these solutions in their processes. Alkali and alkaline earth metals (e.g., Li, Na, K, Mg, Ca, and Ba) can reduce the oxide breakdown voltage of the devices. In addition, transition and heavy metal elements (e.g., Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ag, Au, and Pb) can produce higher dark current. Doping elements (e.g., B, Al, Si, P, As, and Sn) can alter the operating characteristics of the devices. In SACHEM s quality control laboratory, ICP coupled to mass spectrometry is used to simultaneously analyze multiple trace elements in one sample in just 1 to 4 min. This ICP-MS instrument is a state-of-the-art instrument that can provide high throughput and low detection Emits at the parts per thousand level. Trace elemental determination at the parts per thousand level must be performed in a clean room so that trace elemental contamination from airborne particles can be minimized. 

An Intercomparison study of trace element determinations In simulated and real air particulate samples has been published by Camp, Van Lehn, Rhodes, and Pradzynskl ( ). This Involved twenty-two different laboratories reporting up to thirteen elements per sample. The simulated samples consisted of dried solution deposits of ten elements on Mllllpore cellulose membrane filters. In our data analysis a set of energy dispersive X-ray emission results restricted to eight laboratories reporting six elements (V, Cr, Mn, Fe, Zn, Cd) was... 

The composition of HT materials can be approximated as the average composition of all HT materials tested in this study, taking into account the lower and upper concentrations of major, minor, and trace elements determined for each of the three... 

Segura, M., Camara, G, Madrid, G, Rebollo, C., Azcarate, J., Kramer, G. N., Gawlik, . M., Lamberty, A., and Quevauviller, Ph. (2004), Certified reference materials (CRMs) for quality control of trace-element determinations in wastewaters, Trends Anal. Chem., 23,194-202. 

Certified reference materials (CRMs) are mainly applied to validate the analytical procedure developed for routine analysis in order to determine the accuracy of analytical data, the recovery for selected elements, the uncertainty of trace element determination and the detection limits. Otherwise, in solid-state mass spectrometric techniques, such as SSMS, LA-ICP-MS, GDMS, SNMS or SIMS, one point calibration using CRMs has been established as an important calibration strategy to obtain reliable analytical data. The one point calibration is performed using the experimentally determined relative sensitivity coefficients (RSCs) on a suitable CRM with a similar trace/matrix composition. An RSC of a chemical element is defined as the ratio of the measured element concentration (experimentally determined) divided by the certified element concentration (accepted or recommended value of element concentration) in a given matrix. 

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