Trace Determination of Pesticides and their Degradation Products in Water (BOOK REPRINT), Volume 19

Chapter headings and selected papers: Pesticides and their Degradation Products: Characteristics, Usage and Environmental Behaviour. Introduction. Chemical classes and physico-chemical properties of pesticides. Environmental relevance in the aquatic environment. Degradation of pesticides in the aquatic environment. Toxicity and ecotoxicity. Conclusions. References. Quality Assurance Issues: Sampling, Storage and Interlaboratory Studies. Sampling. Storage. Interlaboratory performance studies. References. Chromatographic and Related Techniques for the Analysis and Detection of Pesticides. Introduction. Gas chromatography. Liquid chromatography. Thin layer chromatography. Capillary electrophoresis. Mass spectrometric methods. Conclusions. References. Sample Handling Techniques (Extraction and Clean-up of Samples). Introduction. Extraction and concentration procedures. Clean-up procedures. Conclusion and further developments. References. On-Line Sample Handling Strategies. Introduction. On-line techniques with separation by liquid chromatography. On-line techniques with separation by gas chromatography. On-line solid-phase extraction, supercritical fluid extraction, and supercritical chromatography. Conclusion and further trends. References. Immunochemical Methods and Biosensors. Introduction. Immunoassays. Immunochemical sample preparation methods. Biosensors. Conclusions and perspectives. References. Subject Index.

The book is a critical compilation of analytical methods for the monitoring of pesticides and their degradation products in water. It contains up-to-date material and is the result of the authors' experience in the pesticide analysis field. The book is structured in six chapters, starting from general aspects of pesticides like usage, physicochemical parameters and occurrence in the environment. A second chapter is devoted to sampling from water matrices, stability methods of pesticides in water and quality assurance issues. The general chromatographic methods for pesticides are reported, including the newly developed electrophoresis methods and GC-MS and LC-MS confirmatory analytical methods. Sample preparation methodologies, including off-line and on-line techniques are described in the next two chapters, with a comprehensive list of examples of pesticides and many metabolites, including the use of different GC-methods and LC-methods. The final chapter is devoted to the development of biological techniques, immunoassays and biosensors, for the trace determination of pesticides in water samples.

The book answers a key problem in pesticide analysis: the diversity of chemical functional groups, with varying polarity and physicochemical properties. Pesticides and their metabolites have received particular attention in the last few years in environmental trace-organic analysis. For instance, in the case of groundwater, pesticides use has become a cause for concern. Under the right conditions, pesticides can move through soil into groundwater, a phenomenon once thought improbable. The movement of agrochemicals in surface water flow can be a major problem, especially in the case of water soluble pesticides that are generally transported to estuarine and coastal waters. Estuarine waters feature gradients of both pollutant concentrations and physicochemical characteristics such as salinity, turbidity and pH, and all these parameters must be carefully considered when developing analysis methods for trace organics in estuarine waters.

A key parameter in analytical determination is the environmental sampling. Different protocols and devices are needed for sampling sea-water samples—usually using large sample volumes of more than 50 litres either with LLE or SPE, with the problems encountered due to dissolved and particulate matter—which is different from drinking water and well water sampling. The representativeness of the sampling is also of concern.

Sample preparation of organic compounds from water matrices has been recognized to be a bottleneck and has been traditionally neglected in the literature. During the last few years new adsorbents have appeared—carbon type, polymeric sorbents with high capacity and immunosorbents—which can more efficiently trap the more polar compounds.

Development of advanced automation methods, based usually on solid phase extraction techniques, are examples of commercially available equipment that are of growing importance. These systems are generally coupled to LC and GC techniques.

Sampling and sample handling cannot be regarded as separate techniques in the analytical process and both should be integrated into the whole analytical determination. For this reason, validation and confirmation methods are needed. These serve to check the quality assurance of the developed method. The discussion between multiscreening versus specific analysis methods and the influence of the matrix (ground-, surface- and estuarine-water), is also a point of concern due to the diversity of chemical classes within the compounds of study.

Finally, the use of rapid analysis methods, which refer basically to biological techniques, biosensors and immunoassays are also of growing interest for the determination of pesticides in environmental matrices. These methods are very useful and complementary to conventional GC and/or LC techniques for the determination of pesticides.

For university departments of analytical chemistry and environmental chemistry, analytical departments of chemical industries, environmental organizations and chemical and environmental libraries.