Speciation analysis hyphenated techniques

Applications ICP-MS has become the technique of choice for the determination of elements in a wide range of liquid samples at concentrations in the ng L 1 to [igL-1 range. Typical applications of ICP-MS are multi-element analysis of liquids (even with high solid contents) element speciation by hyphenation to chromatographic techniques continuous on-line gas analysis multi-element trace analysis of polymers and trace analysis in high-purity materials. ICP-MS is routinely used for quality control purposes. 

Principles and Characteristics The fastest growing area in elemental analysis is in the use of hyphenated techniques for speciation measurement. Elemental spe-ciation analysis, defined as the qualitative identification and quantitative determination of the individual chemical forms that comprise the total concentration of an element in a sample, has become an important field of research in analytical chemistry. Speciation or the process yielding evidence of the molecular form of an analyte, has relevance in the fields of food, the environment, and occupational health analysis, and involves analytical chemists as well as legislators. The environmental and toxicological effects of a metal often depend on its forms. The determination of the total metal content... 

The aim of this work was to investigate the arsenic mobilization from the tailings material (200 - 500 pg/g As) into the seepage water (up to 3.5 mg/L As) and the process of seepage water effluent forming an immobilized precipitate (up to 8 % As) in the creek. Different analytical methods for the determination of total concentrations and different sequential extraction methods as well as hyphenated techniques for speciation analysis were applied to follow the way of the arsenic in this environment. 

Trends in mass spectrometry focus on the improvement of instrumentation, of several techniques in order to minimize sample volume, to improve sensitivity and to reduce detection limits. This is combined with increasing the speed of several analyses, with automation of analytical procedures and subsequently reducing the price of analysis. A minimizing of sample volumes means a reduction of waste volume with the aim of developing green chemistry . Furthermore, new analytical techniques involve a development of quantification procedures to improve the accuracy and precision of analytical data. Special attention in future will be given to the development of hyphenated mass spectrometric techniques for speciation analysis and of surface analytical techniques with improved lateral resolution in the nm scale range. 

Sadi, . . M., Vonderheide, A. P., Becker, J. S. and Caruso, J., Multiple Detection Size-Exclusion Chromatography, ACS Symposium Series 893, American Chemical Society, Washington, DC, 168 (2004). Szpunar, J. and Lobinski, R., Hyphenated Techniques in Speciation Analysis. R. M. Smith (ed.) RSC Chromatic Monographs, Cambridge (2003). 

Szpunar, J. and Lobinski, R., Hyphenated Techniques in Speciation Analysis, R. M. Smith (ed.), RSC Chromatic Monographs, Cambridge (2003). 

Figure 1.12 Species-selective hyphenated techniques for speciation analysis.

The nutritional, chemical, biological, and toxicological properties of a chemical element are known to be critically dependent on the form in which it occurs in food. The recognition of this fact has spurred the development of species-selective (speciation) analytical methods for food additives and contaminants. According to the IUPAC s dehnition, speciation analysis deals with the analytical activities of identification and/or measurement of the quantities of one or more individual chemical species in a given sample [1], The analytical approach is usually based on the combination of a chromatographic separation technique with an element-specif>c detection technique. The former ensures that the analyte compound leaves the column unaccompanied by other species of the analyte element, whereas the latter enables a sensitive and specil>c detection of the target element. Coupled (also called hyphenated) techniques have become a fundamental tool for speciation analysis and have been discussed in many published reviews [2D6]. 

The choice of hyphenated techniques available for speciation analysis in foods is schematically shown in Figure 16.1. In the most frequent cases a separation technique, for example, GC, HPLC, electrochromatography or GE, is combined with ICP-MS. 

J. Szpunar, Bioinorganic speciation analysis by hyphenated techniques, Analyst, 125 (2000), 963D988. 

Methods for Speciation Analysis in Human Milk Typically Using Hyphenated Techniques and Off-Line Combinations... 

A strong preference in speciation analysis is to use a separation step that can be combined with a detection step in an on-line system [45]. In such coupling, analytical selectivity relies on the application of different chromatographic or electrophoretic methods, while the use of atomic spectrometric techniques assures high sensitivity and f>t-for-purpose limits of detection (LoDs). However, hyphenated techniques with element-specif>c detection do not provide structural information on the species. If appropriate standards are available, the assignation of chromatographic peaks can be accomplished by spiking experiments. On the... 

K. Wrobel, S. S. Kannamkumarath, K. Wrobel, J. A. Caruso, Environmentally friendly sample pretreatment for speciation analysis by hyphenated techniques, Green Chem., 5 (2003), 250D259. 

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