ABSTRACT
Bioanalytical methods, specifically enzymological and immunochemical methods, have been used for over a generation in clinical and forensic laboratories for the analysis of drugs and the components of physiological fluids. However, relative to most of the physical and chemical methods are discussed thus far, their use for environmental analysis is a recent phenomenon. Enzymes are proteins that serve as catalysts for the thousands of chemical reactions that are always underway in living cells. They represent the largest and most highly specialized class of protein molecules in living matter, each of them catalyzing only a specific reaction type involving only very specific reactants, which are called the enzyme substrates. Some enzymes require so-called co-factors to be present for them to exhibit catalytic activity. Enzyme analyses are almost always based on some form of colorimetry or spectrophotometry, measuring the rate of change of absorbance resulting from either the disappearance of the substrate or the appearance of the product.
