Supelco® researchers have been at the forefront of carbon adsorbent research and product development for more than 40 years. Initial work focused on understanding how thermodynamic and kinetic properties affect the performance of both existing and novel carbons. With knowledge gained from this fundamental research, we developed new, cutting-edge carbon adsorbents with significant advances in technology.
The innovation and high-performance of our specialty carbon adsorbents even resulted in their use for experiments in space. The 1977 Voyager 1 mission through our solar system, 1995 Galileo mission to Jupiter, 2005 Cassini-Huygens mission to Saturn and its largest moon Titan, 2008 Phoenix mission to Mars, and the International Space Station all had Supelco® carbon adsorbents on board.
Here on earth, they are used for:
- Collection media in air sampling devices
- Packings in SPE hardware, purge traps, and GC columns
- Adsorption and desorption of targeted analytes in water, air, soil, serum, etc.
- Bulk-scale purification of gas and liquid streams
- Recovery of synthesized compounds from reaction mixtures
- Supercapacitors and batteries
In contrast with non-specific, low-tech carbon black and activated carbon adsorbents, our specialty carbon adsorbents are expertly engineered materials, with many manufactured from highly pure synthetic polymers. Many of their properties can be modulated, including:
- Shape: either spherical or granular
- Pore number ranging from none, to whatever number is best for a given purpose
- Tapered pores (from macro- to meso- to micro-), increasing thermodynamic and kinetic efficiency
- Through-pore or closed-pore structure, which influences microporous strength and kinetic effectiveness
- Surface pH, from as low as 2.5 to as high as 10.5
Today, we make over 30 different specialty carbon adsorbents ranging in particle size from <0.2 to 850 μm and surface area from 5 to 1,500 m2/g. Any modifications (activation, oxidation, graphitization, surface pH adjustment, etc.) are accomplished through physical means.


The Supelco® line includes carbon molecular sieve (CMS), spherical graphitized polymer carbon (SGPC), and graphitized carbon black (GCB) adsorbents. We also offer sampler kits, a cost-effective way to evaluate several of our products at once.
To learn more about our specialty carbon adsorbents, download a brochure at www.sigmaaldrich.com/carbon.
Carbotrap® Adsorbents for Thermal Desorption
The Supelco® portfolio includes a comprehensive selection of GCB adsorbent tubes – Carbotrap® tubes – that offer superior performance for trapping and thermally desorbing organic compounds. Selection of adsorbent(s) is critical to achieving the best results for thermal desorption: an ideal adsorbent tube will trap and retain compounds of interest for the entire sampling period, then allow total analyte desorption without thermal decomposition. The rate of release should be as rapid as possible to minimize analysis time and provide the most efficient separation. Stable adsorbents ensure the best detection limits by minimizing the possibility of breakdown products interfering with quantification.
Carbotrap® particles are 20/40 mesh, and these large particles allow high flow rates without excessive pressure drops. We make five different Carbotrap® adsorbents, with the relative adsorptive strength from strongest to weakest being X, B, Y, C, and F.
Carbotrap® C and Carbotrap® B are the most widely used, partly because they were introduced the earliest and partly because they complement one another very well in the analyte size range that each can effectively trap/release.
To extend this analyte size range, we introduced Carbotrap® F. This scalable adsorbent is only available as a custom item and has some overlap with C.
Carbotrap® Y provides an analyte size range that can be effectively trapped/released overlapping with both the low end of C and the high end of B.
Carbotrap® X is unlike other GCBs because it is porous (has a closed-pore structure). With the greatest adsorptive strength of our GCBs, it provides a unique bridge between GCB and CMS adsorbents. Our thermal desorption tubes are available in either glass-fritted or stainless-steel tubing with a unique barcode label.
Features and Benefits


- All Carbotrap® products are supplied with our adsorbent technology inside
- More consistent back pressure from tube-to-tube
- Easy-to-read markings on the stainless-steel tubes
- Glass-fritted tubes with a frit at an optimized location
- TDS3™ storage container or brass endcap-sealed preconditioned tubes
- Easy-to-read barcodes resistant to many preconditioning cycles
What do the numbers mean?
Carbotrap® thermal desorption tubes are available in several different series. Carbotrap® 100 tubes have a single adsorbent bed, Carbotrap® 200 have two, and so on up to the 400 series, which has four adsorbent beds.
Watch a 35-min instructional on-demand webinar to learn more about choosing the right adsorbent for your thermal desorption gas chromatography application, and download our brochure at SigmaAldrich.com/thermaldesorption