| Trace element speciation has become an important issue in different fields of science. Research interests have moved from total element composition of the sample toward characterization of species that are responsible for biochemical and geochemical behavior of the elements. Information on elemental speciation in environmental and clinical material is vital in studies on possible mechanisms of element transport and/or degradation in the environment, element bioavailability and on possible metabolic pathways within living organisms. The current analytical approach for speciation analysis involves using hyphenation techniques, based on the combination of separation and detection steps into one while operating an on-line system. Both high performance liquid chromatography and capillary electrophoresis were the primary separation techniques utilized in this work. The inductively coupled plasma mass spectrometer was the technique of choice for element specific detection and as part of hyphenated systems for speciation analysis. The use of inductively coupled plasma mass spectrometry allows extremely low detection limits for the majority of the elements, has the advantage of linearity over a wide dynamic range, multi-elemental detection capability and the ability to perform isotopic analysis.; The two most important features of an analytical tool suitable for speciation analysis are good selectivity and high sensitivity. However, the design of the analytical procedure is difficult, owing to the complex composition of the real-world sample, the diversity of physicochemical forms of the element, their lability and low concentrations. Sample preparation methods such as solid phase microextraction (SPME), solid phase extraction (SPE) and liquid-liquid extraction have been commonly used to overcome some of these difficulties. Thus improved sample collection, extraction, and purification techniques can help to overcome the problems associated with complex sample matrices.; The above techniques were used separately or in combination for elemental speciation in food, pharmaceutical and environmental samples. These included the distribution of selenium and arsenic in various nuts, elemental association to different molecular weight fractions in Brazil Nuts, degradation products of levothyroxine in pharmaceutical tablets and iodophenols in river water samples. |
