Thermal Desorption Sorbent Tubes
For (Sub-) ppb VOC Measurements

High sensitivity High recovery Reusable

Thermal Desorption Sample Tubes Downloads

Thermal Desorption
SKC sorbent technology research has produced superior materials for the collection of organic compounds for thermal desorption. Thermal desorption techniques offer the advantage of greatly improved analytical sensitivity. Because a solvent is not used, the collected sample is not diluted and, in most cases, analytical recovery is so close to 100% that desorption efficiency corrections are not required.

Sorbents
To be suitable for thermal desorption, sorbents must meet exacting specifications that include:

• Low contaminant background
• High thermal stability
• Sufficient adsorptive strength to retain components of interest, but release them quickly when heat is applied

Anasorb® 747 (20/40 mesh size and 980 m²/gm surface area)
This beaded active carbon has the capacity for organic vapors similar to petroleum-based and coconut-shell charcoals. It also can be used to sample nonpolar organic compounds.

Anasorb GCB1 (20/40 mesh size and 100 m²/gm surface area)
Anasorb Graphitized Carbon Black 1 (GCB1) has a moderate surface area and is equivalent to Carbotrap ® B (20/40) and Carbopack B (60/80). This sorbent has proven to be valuable for sampling compounds of intermediate to high volatility.

Anasorb GCB2 (20/40 mesh size and 10 m²/gm surface area)
This sorbent has a low surface area and is equivalent to Carbotrap C (20/40) and Carbopack C (60/80). Anasorb GCB2 is useful in collecting semi-volatile organic compounds (SVOCs).

Carbosieve S-III (60/80 mesh size and 975 m²/gm surface area)
This carbon-based molecular sieve has properties similar to the obsolete Anasorb CMS and replaces it in SKC thermal desorption tubes. Carbosieve S-III has a high capacity/breakthrough volume for small molecules and is moderately hydrophilic. It can be used for the lower boiling compounds such as halogenated hydrocarbons and alcohols.

Chromosorb® 106 (60/80 mesh size and 700 to 800 m²/gm surface area)
A porous polymer sorbent, Chromosorb 106 is used to trap low-boiling hydrocarbons, benzene, labile compounds, and volatile oxygenated compounds. This hydrophobic sorbent is the least polar polymer in the Chromosorb family and is functionally similar to Anasorb 727.

Tenax® TA (20/35 or 35/60 mesh size and 30 to 35 m²/gm surface area)
Tenax TA is a traditional sorbent (porous polymer) for trapping medium to high boiling compounds; it is especially useful for low concentrations because of its low background. Tenax TA is hydrophobic and is suitable for use in EPA Method TO-17 or IP-1B and other thermal desorption applications.

Tenax GR (20/35 mesh size and 35 m²/gm surface area)
This Tenax/graphite composite extends the range of Tenax to lower boiling compounds. It retains the ability of Tenax to be cleaned easily to a very low background and is widely used in thermal desorption applications.

Carbograph 5TD (20/40 mesh size and 560 m²/gm surface area)
This is a medium strength sorbent for collecting hydrocarbons in the boiling point range of 50 to 150 C. It is hydrophobic and has low artifact formation.

Thermal Desorption Tube Selection
All SKC thermal desorption tubes are sealed with PTFE end caps and marked with a permanent serial number. When ordered, SKC thermal desorption tubes receive extensive thermal conditioning that remains valid for 30 days. Glass transport tubes and Swagelok® fittings are available as accessory items.

Table Notes

†	Anasorb GCB1 is equivalent to Carbotrap B.
Note:	EPA methods allow some flexibility accommodating similar sampling protocols, however, such flexibility places documentation responsibility on the user. For a detailed explanation, refer to the methods.

Accessories	Qty.	Cat. No.
Glass Transport Tubes, for 3.5-inch (88.9-mm) length tubes	5	226-300
PTFE Ferrules, set of 2	set	P30121
Swagelok Fittings, for 0.25-inch (6.35-mm) OD tubes, set of 2	set	P50291

Custom Tubes Available
For specific applications, SKC will manufacture custom thermal desorption sorbent tubes to meet your specific requirements. Download the Custom Sorbent Tube Order Form in PDF format. Complete the form and fax it to your SKC representative, contact your SKC representative, or call the SKC Sales Department at 724-941-9701 for more information.

Custom Sorbent Tubes for Thermal Desorption Order Form (PDF)

Thermal Desorption Tubes Spec. Sheet (PDF)