Technical innovation in trace organic analysis from Markes

Pioneering new developments in trace organic analysis

For over 20 years, Markes International has pioneered analytical thermal desorption (TD) instrumentation and associated sampling equipment. Here are our most important breakthroughs:

• Inert valving – A patented valve design makes all our TD systems compatible with the widest possible range of VOCs and SVOCs, from C₂ to C₄₄ as well as thermally labile species.
• Re-collection of split flows – Splitting the sample flow during the thermal desorption process, and collecting the unanalysed portion onto a clean sorbent tube overcomes the ‘one-shot’ drawback of older TD systems, and allows valuable samples to be re-analysed.
• Multi-Gas technology – for the first time, enabling certified thermal desorption instruments to be run with a choice of carrier gases: helium, nitrogen and hydrogen.
• Cryogen-free operation – The electrically-operated Peltier modules used to cool the focusing trap in Markes’ systems are much cheaper to run than the expensive liquid cryogen systems used in other TD instruments.
• Backflush desorption of the focusing trap – Collecting the sample onto the sorbent tube or focusing trap in the opposite direction to desorption (‘backflush desorption’) allows use of multiple sorbent beds, extending the range of compounds that can be collected and analysed from a single sample.
• Multi-mode sample extraction with multi-step enrichment – Our Centri platform was the first to offer headspace, SPME, HiSorb sorptive extraction and thermal desorption on one platform. With the added capability for trap-based preconcentration, Centri gives analysts maximum versatility for liquid, solid and gaseous samples.
• Sample stacking – On the Centri platform, multiple samples (from the same vial or from different vials) can be combined onto a single focusing trap before desorption to the GC, greatly improving sensitivity.
• Electronic control of gas flows – Using electronic controllers means that it’s possible to accommodate differing flow-path impedances at different stages of operation. This stabilises GC retention times, which is especially important in complex analyses.
• Diffusion-locking technology for sorbent tubes – Our patented SafeLok tubes provide unrivalled protection for trace and toxic samples, while our DiffLok caps eliminate the capping and recapping of sorbent tubes in high-throughput studies.
• Removal of water from on-line and canister air streams – Trap-based water removal using the Kori-xr module enables polar species and monoterpenes to be reliably monitored in on-line and canister air streams, without the analyte loss that is a problem with other water-management techniques.
• Tube tracking – Introduced in 2007, our patented TubeTAG system enables tube history and sample information to accompany a tube throughout its lifetime.
• Advanced software – Our Markes Instrument Control system for both our TD instruments and for Centri has been continuously updated to offer the latest advances in ease of use – including pre-loaded methods for faster setup, and intelligent diagnostics for improved productivity.