Enzymes analytical methods utilizing

The need to understand the fate of pesticides in the environment has necessitated the development of analytical methods for the determination of residues in environmental media. Adoption of methods utilizing instrumentation such as gas chro-matography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS), liquid chromatography/tandem mass spectrometry (LC/MS/MS), or enzyme-linked immunosorbent assay (ELISA) has allowed the detection of minute amounts of pesticides and their degradation products in environmental samples. Sample preparation techniques such as solid-phase extraction (SPE), accelerated solvent extraction (ASE), or solid-phase microextraction (SPME) have also been important in the development of more reliable and sensitive analytical methods. 

During his approximately fifty-year career in science and technology, Payen published about 200 papers in the major French scientific journals. These described research on dextrin, sugar, bitumen, lignin, cellulose, starch, the enzyme diastase, charcoal, potato, waste utilization, analytical methods, plant and animal nutrition, rubber, gutta percha, manure, water supply, and phylloxera. 

The discussion up to now has only been to determine analytes that are substrates of enzymes. The reason is that substrates are the best analytes of enzyme analytics because they fully utilize the major advantage of enzymes - their high specificity. In contrast, the analysis of effectors, except for cofactors participating in the catalytic centers, always brings a danger of interferences. Thus, some kind of a preliminary sample purification is often necessary which complicates the methods. 

Nowadays, antibodies are utilized in numerous immunoanalytical methods. Those widely used in practice, such as radioimmunoassays, fluoroimmunoassays and enzyme-linked immunosorbent assays (ELISA), require labelled reagents. Millions of ELISA tests for diagnostics of various diseases are daily performed in clinical laboratories. The detection of analytes by two-antibody "sandwich" ELISA, is schematically outlined in Figure 3. 

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