Speciation of Halogen Compounds

WUILLOUD, RODOLFO G.; ALTAMIRANO, JORGELINA C.

Handbook of Elemental Speciation II: Species in the Environment, Food, Medicine and Occupational Health

Wiley & Sons

Lugar: Chichester, England; Año: 2005; p. 564 - 597

Halogenated organic compounds have caused high public concern as organic pollutants. Compounds like dichlorodiphenyltrichloroethane (DDT), polychlorinated biphenyls (PCBs) and chlorinated dioxins have become symbols of global environmental pollution. Scientific investigations of specific organohalogens have shown that many of them are toxic, persistent and subject to bioaccumulation in food chains. Additionally, the understanding of generation mechanisms and possible sources of halogenated volatile organic compounds have become fundamental for complete information on the different volatilization pathways into the atmosphere. As it is well known, the presence of halogens in the atmosphere is an issue of particular environmental concern due to their roll on the deterioration of the ozone layer. On the other h and, the essential character of some halogens, such as iodine and the growing evidence for bromine, justify most of the research done on these elements in biological systems. For the same reason, determination of halogens in food is of high importance to perform nutritional studies. Consequently, the development of new analytical methodologies to perform speciation analysis for this group of elements and their compounds have been propelled by the increasing relevance halogens have to environmental, biological and nutritional studies. Moreover, the application of highly sensitive detection techniques is important for speciation studies where the individual amount of the species can be a minimal fraction of the total elemental concentration. Many analytical methodologies focused on determining halogenated species, particularly organohalogens, have been developed and proposed in the last few years. They mainly consist of an on-line coupling of a highly efficient separation technique such as chromatography or electrophoresis to an element specific detector based on the use of plasmas as excitation - and/or ionization sources. Consequently, the most recent advances in the development of analytical methodologies involving the use of this type of hyphenated technique will be discussed.