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Multi-element technique

Table 8.29 shows the main characteristics of ICP-AES as a fast multi-element technique. Analytical figures of merit for ICP emission spectrometers are... [Pg.621]

The introduction of EU directives on Waste Electrical and Electronic Equipment and Reduction of Hazardous Substances has highlighted the need for precise and repeatable elemental analysis of heavy metals in the plastics production process. X-ray fluorescence (XRF) spectroscopy has emerged as the most economical and effective analytical tool for achieving this. A set of certified standards, known as TOXEL, is now available to facilitate XRF analyses in PE. Calibration with TOXEL standards is simplified by the fact that XRF is a multi-element technique. Therefore a single set of the new standards can be used to calibrate several heavy elements, covering concentrations from trace level to several hundred ppm. This case study is the analysis of heavy metals in PE using an Epsilon 5 XRF spectrometer. [Pg.30]

Hydride/vapour generation techniques provide extremely good sensitivity. When coupled to continuous flow methodologies for use in routine analysis, simple and reliable analytical techniques are provided. TTie extension of chemistries and sample transfer systems to provide analytical protocols to cope with a wider range of elemental analyses should be pursued in the search for lower detection levels. While multi-element techniques offer very low levels of detection, the use of specific single element analytical instruments with detection capabihties similar to those described above may be the best route for routine laboratories with high sample throughput. [Pg.149]

For analysis of solutions, ICP-mass spectrometry (ICP-MS) is very promising (Houk et al., 1980 Houk, 1986 Bacon et al., 1990). Recent advances in separation and preconcentration techniques are discussed by Horvath et al. (1991). Bacon et al. (1990) report that although ICP-MS is a multi-element technique, recent papers tend to concentrate on a small number of target elements. With isotope dilution mass spectrometry (IDMS), detection limits are further reduced (Heumann, 1988) IDMS is also suitable for accurate speciation in very low concentration levels of elements (Heumann, 1990). For the direct analysis of solid samples, glow discharge mass spectrometry (GD-MS) (Harrison etal., 1986) is of interest. Tolg (1988) has suggested that a substantial improvement in the absolute detection power of GD-MS, as applied to micro analysis, can be expected, at least in comparison with the ICP as ion source. [Pg.256]

Kohiyama et al. (1992) reported mean levels of nickel, iron and copper of 0.03, 0.30 and 0.04 mg/kg, respectively, in 10 samples of cocoa butter. Baxter et al. (2001) found comparable results from the determination of 23 elements in 42 cocoa butters and 22 CBA fats, mostly of known geographical origin and processing history, by the sensitive multi-element technique of inductively coupled MS. No distinction could be made between the cocoa butters based on geographical origin or deodorization, and the very low levels of most elements in the CBA fats meant that their presence in mixtures with cocoa butter could not be detected. [Pg.85]

ICP-MS is a multi-element technique suitable for the analysis of liquid samples, which provides higher selectivity and detection power and LoDs lower than other multi-element techniques, such as ICP-AES. These characteristics make ICP-MS an excellent tool for the detailed characterization of the elemental composition of beverages. In this context, ICP-MS was the technique selected for the determination of 31 trace elements in wine at concentrations ranging from 0.1 to 0.5 ng ml-1 [82]. Samples were diluted 1 + 1 and it was investigated whether a matrix effect derived from the presence of ethanol could be overcome by using a microconcentric nebulizer with membrane desolvation. The authors compared their results with those obtained using a conventional Meinhard nebulizer and concluded that the matrix effect observed could only be minimized by using an internal standard with the Meinhard nebulizer, but not with the other one. [Pg.473]

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. [Pg.212]

In order to demonstrate the analytical capabilities of LI-MS, the results it provided for glass samples were compared with those obtained using other multi-element and microanalytical techniques to determine 30 trace elements [195]. This comparison revealed the number of elements that can be determined by LI-MS to be similar to that of other multi-element techniques such as instrumental neutron activation analysis (INAA) or LA-ICP-MS. However, INAA was unable to determine some geochemically interesting trace elements such as Nb and Y, and LA-ICP-MS analyses were occasionally disturbed by the formation of argon clusters. In contrast to LA-ICP-MS, LI-MS can also measure single-isotope elements such as Nb, Y, Pr and Ho also, it requires no wet chemistry. [Pg.494]

Despite these difficulties, this multi-element technique provides superior sensitivities and can be anticipated to become the technique of choice for the ultra-trace determinations of nutrients/metallic contaminants in foods. [Pg.173]

To summarise, FAAS is very easy to use. Interferences are known and can be controlled. Extensive application information is also readily available. Its precision makes it an excellent technique for the determination of a number of commonly analysed elements at higher concentration in polluted soil samples. Its main drawback is its speed in relation to multi-element techniques such as ICP-AES and ICP-MS. Where direct-aspiration flame atomic absorption technique does not provide adequate sensitivity, reference is made to specialised techniques (in addition to graphite furnace procedure) such as the gaseous-hydride method for arsenic, antimony and selenium and the cold-vapour technique for mercury. [Pg.75]

At irradiation with thermal neutrons, stable isotopes of mercury and many other elements are converted into radioactive daughter isotopes, that can be identified and quantified by high resolution gamma spectrometry. The irradiation is usually carried out in a nuclear reactor with thermal neutron flux densities of lO -IO cm s NAA is well established as a multi-element technique, and has a reputation of good accuracy. Separation and specification of mercury compounds is, however, not possible, since organic mercury turns into inorganic at irradiation (Rottsohafer et al., 1971). [Pg.429]

Multi-elemental techniques versus single element techniques... [Pg.188]

Although the presently realised continuum-source AA spectrometers are still operated sequentially for multi-element detection, it may be anticipated that, with use of suitable optics and multi-array detectors, this method wiU become a truly simultaneous multi-element technique [10]. [Pg.440]

When a primary X-ray with sufficient energy strikes a sample, the inner electrons may be ejected. The excited atoms can emit characteristic radiation during the subsequent process of de-excitation. The emitted X-rays carry information about the elemental composition of the specimen in the irradiated region which is called X-ray fluorescence analysis (XRF). XRF is also a multi-elemental technique and more detailed information about XRF can be found in Chapter 3. [Pg.362]

Many analytical techniques have been applied to the determination of minerals and trace elements but the most successful are those based on atomic spectroscopy. The techniques included in the subsequent sections afford the sensitivity required to measure concentrations below 1 ppm in specimens of just a few pL or mg with almost total specificity and relatively few interferences. As situations of deficiency and toxicity are investigated, analytes may be present at very low or very high concentrations within the same specimen type. Therefore, techniques with differing sensitivities may be used, as appropriate, for the same application. Many biomedical investigations require the measurement of just one or two metals. Consequently, multi-element techniques are not necessarily as important as in some other application areas. Nevertheless, there are situations in which this facility does become important. [Pg.142]

Fordham, P. J., GramshavyJ. W., Castle, L., and Crews, H, M. (1995). Determination of trace elements in food contact polymers by semi-quantitative inductively coupled plasma mass spectrometry. Performance evaluation using alternative multi-element techniques and in-house polymer reference materials.J.H a/./ /. Spectrom. 10(4), 303. [Pg.213]

Representative spectra from a lanthanide and an actinide are shown in figs. 21 and 22. The most abundant analyte peaks are from monatomic ions (M" ), and these are observed at sensitivities of 10 -10 count s per mg in solution. Ion count rates as low as 2counts s can be distinguished from the background, so the detection limits for most elements are of the order of 10-100 ng/ . At present, these powers of detection are superior to those obtainable with any other common multi-element technique. Atomic absorption spectrometry with electrothermal vaporization does provide detection limits in a similar range but is generally used only for single-element determinations. [Pg.410]


See other pages where Multi-element technique is mentioned: [Pg.610]    [Pg.640]    [Pg.101]    [Pg.72]    [Pg.263]    [Pg.473]    [Pg.129]    [Pg.299]    [Pg.22]    [Pg.169]    [Pg.85]    [Pg.91]    [Pg.277]    [Pg.32]    [Pg.377]    [Pg.44]    [Pg.356]    [Pg.455]    [Pg.41]    [Pg.40]   
See also in sourсe #XX -- [ Pg.470 ]




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Elemental Techniques

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