Analytical features of pervaporation methods

This section deals with the basic analytical properties (sensitivity, selectivity and precision) of pervaporation-based methods. 

The sensitivity of a method involving pervaporation essentially depends on the efficiency of the separation step. The efficiency of pervaporation can be adjusted in order to fit the signal provided by the analyte or its reaction product to the linear portion of the calibration curve for a given method, thus avoiding the need for a dilution or concentration step. A number of approaches to increasing and decreasing pervaporation efficiency exist. 

Solid sample treatments involving the removal of volatile species 

In multideterminations, and also when the target volatile analytes possess different boiling points, the pervaporation unit can be used at different temperatures to ensure selective separation of the species of interest. Use of a heating system allowing reproducible control of time and temperature is obviously mandatory here. 

Discrimination between polar and non-polar volatile analytes can be accomplished by using microwave irradiation of the donor chamber in order to facilitate the evaporation of polar species. Non-polar ones can then be evaporated by conventional heating (whether electrical or by use of a water bath). 

---