Volatilization gravimetric methods based

Unlike precipitation gravimetry, which is rarely used as a standard method of analysis, gravimetric methods based on volatilization reactions continue to play an important role in chemical analysis. Several important examples are discussed in the following sections. 

Gravimetric methods based on precipitation or volatilization reactions require that the analyte, or some other species in the sample, participate in a chemical reaction producing a change in physical state. For example, in direct precipitation gravimetry, a soluble analyte is converted to an insoluble form that precipitates from solution. In some situations, however, the analyte is already present in a form that may be readily separated from its liquid, gas, or solid matrix. When such a separation is possible, the analyte s mass can be directly determined with an appropriate balance. In this section the application of particulate gravimetry is briefly considered. 

The two most common gravimetric methods based on volatilization are those for determining water and carbon dioxide. 

Volatilization method of analysis A variant of the gravimetric method based on mass loss caused by heating or ignition. 

Methods u.sed to measure the permeability of polymers to vapors fall broadly into two categories, namely those for water vapor and those for volatile liquids. In both cases the most common measuring technique is the weight change or gravimetric method. Several test standards are based on this. Other methods include techniques similar to those used for gases. 

While total organic matter is defined as arbitrary physical fractions (dissolved, particulate, and volatile), the recommended methods for their measurement are similar. An outline of the methods used for analysis of organic carbon in sea-water samples is shown in Fig. 7. Most of these methods are based on oxidation of organic matter to CO2 which is determined by volumetric, gravimetric, conductometric, titrimetric, or coulometric methods... 

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