Offline and online solid phase extraction/preconcentration of inorganics

Abstract

Solid phase extraction (SPE) is a powerful technique for preconcentration/removal or separation of trace and ultra trace amounts of toxic and nutrient elements. SPE effectively simplifies the labour intensive sample preparation, increase its reliability and eliminate the clean up step by using more selective extraction procedures. The synthesis of sorbents with a simplified procedure and diminution of the risks of errors shows the interest in the areas of environmental monitoring, geochemical exploration, food, agricultural, pharmaceutical, biochemical industry and high purity metal designing, etc. There is no universal SPE method because the sample pretreatment depends strongly on the analytical demand. But there is always an increasing demand for more sensitive, selective, rapid and reliable analytical procedures. Among the various materials, chelate modified naphthalene, activated carbon and chelate functionalized highly cross linked polymers are most important. In the biological and environmental field, large numbers of samples are to be analysed within a short span of time. Hence, online flow injection methods are preferred as they allow extraction, separation, identification and quantification of many numbers of analytes. Chapter 1 deals with general introduction to solid phase extractive preconcentration and techniques adopted for the preconcentration. Chapter 2 describes the determination of mercury (II) in Biological samples, such as hair using quinolin-8-thiol modified naphthalene as a solid phase extractant. The preparation of above mentioned material is very simple and the mercury (II) coprecipitated on naphthalene is simply dissolved in acetone for subsequent determination using dithizone procedure. Various parameters that influence the preconcentration of mercury (II) by solid phase extraction are systematically optimized and results obtained are discussed in this chapter.