One of the main reasons for the fact that inorganic polyphosphates were a neglected area of research over a long period of time was the lack of reliable experimental tools for the study of these polymers. In recent years, the range and specificity of the methods available have been revolutionized by the development of novel techniques especially in the field of molecular biology and their application to the investigation of polyphosphates. In particular, the availability of specific polyphosphate-dependent enzymes has been a considerable progress for the development of definite and exact methods. However, for certain questions, optimal methods are still missing.The aim of this chapter is to summarize and to illustrate the most important and most widely used methods for investigation of polyphosphates, with their advantages and disadvantages. The efficiency and applicability of nuclear magnetic resonance spectroscopy for studying polyphosphates is described in Chapter 13. Furthermore, novel promising methods for the isolation and quantification of polyphosphate as well as for the measurement of polyphosphate-dependent enzyme activities by using the power of specific enzymes are explained and documented in Chapter 12.
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Preparation of Inorganic Polyphosphates
Chemical SynthesisFormally, inorganic polyphosphates are formed by condensation of orthophosphate under formation of phospho anhydride bonds. Three different groups of basic structures can result: linear, branched and cyclic molecules. The latter are also called metaphosphates. When orthophosphoric acid or its salts are heated these substances form condensates by leaving of water.