Steps of the DPHSE process

The steps involved in a dynamic pressurized hot solvent extraction process are similar to those of ASE, with only a few, slight differences — particularly at the last stages. Thus, the DPHSE process involves the following five steps (see Fig. 6.13)  

High-pressure, high-temperature solvent extraction 

Dynamic extraction at a fixed solvent flow-rate 

No purging of the system with a gas after extraction is required in this mode (Fig. 6.10) as the solvent is continuously circulated through the sample to sweep extracted analytes. 

The extraction cell is filled with sample, as in ASE. A fibreglass filter [34,43,157] can be placed between the sample and metal frits to avoid clogging of the latter. It should be noted that the solvent is continuously circulated in the same direction through the cell 

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