Passive Thermal Desorption Tubes

  • Meets specification of U.S. EPA 325A and UK HSE MDHS 104
  • EPA-validated sampling rates available for benzene, toluene, ethylbenzene, xylenes and many other VOCs
  • Allows for extended sample times for low-level measurements
  • Unique identification number and bar code
  • Airflow direction and cap placement arrow indicators printed on tube
  • Reusable after laboratory conditioning
  • Ideal for establishing average airborne concentrations of additional VOCs of concern

Note: All tubes are conditioned and quality control tested to assure low background

SKU: 226-520 Category:

Description

The SKC Passive Thermal Desorption tubes offer an easy and accurate way to sample low-level VOCs over extended periods of time. They meet the requirements of EPA 325A regulation for fence-line monitoring of benzene at petroleum refineries with extended sample periods of 14 days. SKC supplies sampling rates for other VOCs for other applications. A weatherproof shelter is available for protecting samplers during outdoor sampling.

The tubes are standard-sized SilcoNert 2000® deactivated Stainless Steel Thermal Desorption tubes with Swagelock fittings; when they are deployed a diffusion cap is connected to one end. The diffusion cap works the same way as a front plate on a passive badge, and has a small screen inside which also keeps out particulates/insects.  SilcoNert 2000® is used as a coating to deactivate the stainless steel EPA 325 Passive TD Tubes for Benzene. This process improves corrosion resistance, inertness, and hydrophobicity for better detection limits and system performance. Tubes are deployed inside a custom-made shelter for outdoor use, which can hold up to 4 tubes at a time, and keeps them pointing diffusion-cap downwards.

Applications include:

  • Fenceline monitoring
  • Indoor air sampling
  • Vapour intrusion studies

 

SPECIFICATIONS

Tube Material Stainless Steel coated with SilcoNert® 2000, sealed with brass Swagelok screw caps fitted with PTFE ferrules
Dimensions 89 x 6.35 mm (3.5 x 0.25 inch) OD
Analysis GC-FID or GC-MS

 

 

THERMAL DESORBTION TUBES

Description Pack Size Part Number
SKC Passive TD Tubes *

6.35 mm (1/4 inch) OD deactivated stainless steel tubes filled with pre-conditioned sorbent and supplied with diffusion caps and brass Swagelok screw caps with PTFE ferrules. Choice of sorbents:

Carbopack X, 400mg
Anasorb GCB1†  , 400mg

 

10
10

 

226-520
226-521

Diffusion Caps 10 226-525
Swagelok Fittings for ¼ inch OD x 3½ inch L tubes, set of 2 Each P50291
PTFE Ferrules, set of 2 Each P30121
Weatherproof Shelter, which can hold up to 4 tubes at a time, and keeps them pointing diffusion-cap downwards. 10 cm diameter x 13.7 cm length (4 x 5.5 inch) Each 226-526

* Tubes must be used within 30 days of conditioning
† Equivalent to Carbopack B/Carbograph 1

 

VALIDATED UPTAKE RATES

VALIDATED UPTAKE RATES

Compound Carbopack X mL/min Anasorb GCB1 mL/min #
Benzene 0.67 ±0.06 0.63 ±0.07
Carbon tetrachloride 0.51 ±0.06 N/A
Chlorobenzene 0.51 ±0.06 N/A
3-Chloropropene 0.51 ±0.3 N/A
p-Dichlorobenzene 0.45 ±0.05 N/A
1,1-Dichloroethane 0.57 ±0.1 N/A
1,2-Dichloroethane 0.57 ±0.08 N/A
1,1-Dichloroethene 0.57 ±0.14 N/A
1,2-Dichloropropane 0.52 ±0.1 N/A
Ethylbenzene 0.46 ±0.07 0.50
Styrene 0.50 ±0.14 N/A
Tetrachloroethene 0.48 ±0.05 N/A
Toluene 0.52 ±0.14 0.56 ±0.06
1,1,1-Trichloroethane 0.51 ±0.1 N/A
1,1,2-Trichloroethane 0.49 ±0.13 N/A
Trichloroethene 0.50 ±0.05 N/A
m,p-Xylene 0.46 ±0.09 0.47 ±0.04
o-Xylene 0.46 ±0.12 0.47 ±0.04

# SKC Anasorb GCB1 is equivalent to Carbopack B/Carbograph 1.

 

DOCUMENTS

Passive Thermal Desorption Tube Instructions