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Thermal Desorption (TD)

Thermal desorption (TD) arose out of the need to improve upon conventional sample preparation techniques such as solvent extraction, solid-phase microextraction, purge-and-trap and static headspace. It gives greater sensitivity than these techniques and can be used for a wider range of compound classes ranging in volatility from C2 to n-C44 hydrocarbons. TD is also applicable to a wide range of sample types – solids (using dynamic headspace, headspace sorptive extraction or direct desorption), liquids (using immersive sorptive extraction) and gases (using pumped sampling, passive sampling, on-line sampling or canisters). It is safer and more environmentally friendly than solvent extraction, is easily automated, easy to validate and complies with key standard methods.

TD is a versatile preconcentration and injection technique for gas chromatography, which is often used to automate analysis of volatile and semi-volatile organic compounds in air, gas and materials. Modern sorbent technology and sophisticated TD instrumentation can be optimised to capture the widest range of analytes for both target and untargeted analysis whilst ensuring selective purging of interferences such as solvents and water from the analytical system. The adsorbent trapping and thermal desorption process can handle wide dynamic and analyte ranges, allowing for the detection of ultra-volatiles to semi-volatiles in concentrations ranging from part-per-trillion (ppt) to low-percent levels. TD also greatly improves sample throughput and is easily automated and validated, saving time and manpower.