Selected Trapping Materials

Material Mesh Size

Optimum Molecular Weight Range

   Max.     Operating Temp.

Surface Area    _m²gram 

Strengths / Weaknesses

Glass Beads 60:80

Semi-volatiles, solids at room temperature

>350°C

<5

Thermally stable, inert, low surface area. Acts as a filter at tube inlet, segregating higher boiling compounds from more tenacious adsorbents.Suitable only for large molecules.

Silica Gel 60:80 80:100

Low-boiling polar compounds, esp. chlorinated and sulfur groups

750

Within optimum range, good adsorption / desorption qualities. Especially useful for separating chlorinated or sulfur compounds from matrices with hydrocarbon interferences.Retains water.

Tenax-TA™ 20:35  60:80

C₆ to C_30s, C₂  to  C₅ depending on functional group

350°C

35

Within optimum range, will readily release what it adsorbs. Does not react with materials. Low affinity for water.May form some artifacts when heated, typically CO₂ , benzene, and toluene.

Tenax-  GR™20:35 60:80

              Volatile organic compounds

350°C

An alternative to other carbon based adsorbents for low boiling compounds. Lower affinity for water than Tenax-TA.Lower breakthrough volumes, typically, than carbon molecular sieves

HayeSep D™60:80

Low molecular weight compounds, esp. halogen and sulfur groups

290°C

800

Good backup for Tenax where carbon based adsorbents are unsuitable. Retains many low boiling compounds that breakthrough Tenax, esp. in saturated atmospheres.Moderate artifact level at upper temperature limit. High pressure drop.

Chromosorb 106™60:80

Low molecular weight, volatile compounds.

225°C

750

An alternative to other polymeric and carbon based adsorbents for low boiling compounds.Low temperature limit, high artifact level. Batch to batch variations.

Carbonaceous Materials

Carbotrap™20:40 

C₅ to C₁₂

>400°C

100

High thermal stability. Low back-pressure. Hydrophobic.Lower desorption efficiency than Tenax for higher molecular weight compounds when used for sampling in saturated atmospheres, i.e. during thermal stripping.

Carbotrap CJ20:40

Heavy organics:  PCBs, PNAs, other large molecules

>400°C

10

Same as Carbotrap

Coconut Charcoal60:80

C₂ to C₅ volatile organic compounds

>400°C

1070

High capacity / breakthrough volume for low boiling compounds. Greater retention capability than Carbosieve SIII.Lower desorption efficiency than Carbosieve SIII. Tendency to retain water

Carbon Molecular Sieves

Ambersorb XE-340J (Carboxen-563J)20:45

C₃ to C₅  volatile organic compounds

>400°C

510

High capacity / breakthrough volume for low boiling compounds. Low back-pressure. Hydrophobic.Low desorption efficiency for  polar compounds. May produce sulfur compounds as artifacts, typically SO₂.

Carbosieve  SIIIJ60:80

C₂ to C₆  volatile organic compounds

>400°C

820

High capacity / breakthrough volume for low boiling compounds. Less water retentive than charcoal. Better desorption efficiency than charcoal for low-boiling hydrocarbons.Low desorption efficiency for polar compounds. Less retentive capability than charcoal.

Carboxen 1000J60:80

C₂ to C₆ volatile organic compounds

>400°C

1200

Better desorption efficiency than Carbosieve SIII.Not as retentive as SIII. May produce sulfur compounds as artifacts, typically SO₂.