Diffusive TD Tubes
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.
- 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
Applications include:
- Fenceline monitoring
- Indoor air sampling
- Vapour intrusion studies
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.
Note: All tubes are conditioned and quality control tested to assure low background
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 |
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 | 0.5 |
| 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.
Passive Thermal Desorption Tubes
| Description | Pack Size | Part Number |
| SKC Passive TD Tubes * | 10 | 226-520 |
| 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: | 10 | 226-521 |
| Carbopack X, 400mg | ||
| Anasorb GCB1† , 400mg | ||
| 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 | ||
Documentation
