User`s guide

Theory of Thermal Desorption
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in the environmental field where samples frequently contain a
significant amount of water.
Packed cold traps can function with higher carrier gas flow rates
than capillary cryofocusing devices. This facilitates the introduction
of one or more split points into the sample flow path, which, in turn,
allows independent control of the gas flows during primary
desorption, secondary desorption and chromatographic analysis.
Using a packed cold trap, therefore, enables flow rates of 10 to 200
mL/min to be used at the same time as optimum narrow bore
capillary column flow rates of 0.5 to 1 mL/min.
Very volatile species such as ethane, vinyl chloride and nitrous oxide
can be retained on packed cold traps without the use of liquid
coolant.
A packed cold trap also prevents higher boiling species from being
lost through aerosol formation.
Practical Applications of Thermal
Desorption
Environmental Monitoring
Environmental monitoring is a major application for thermal
desorption, and can be divided into three distinct categories:
1. Workplace air monitoring for vapor phase, primarily
organic, pollutants. Typical concentrations are in the
order of ppm.
2. Environmental air monitoring for vapor phase, primarily
organic, pollutants. Typical concentrations in the order
of ppb.
3. Purgeable volatiles in water and sediment
Extraction of Organic Volatiles from Liquids
and Solids
In addition to environmental applications, thermal desorption is used
extensively for the extraction of organic volatiles from many sample