Digestion Rotor Technology

Flexibility and performance that make the difference

The SK-15, MAXI-44 and MAXI-24 HP digestion rotors feature unique Milestone MDR technology to control the inner pressure of all vessels in complete safety. This 'vent and reseal' technology for pressure release is the foundation of Milestone's leadership in microwave digestion.

System description

The SK-15, MAXI-44 and MAXI-24 HP offers, high quality digestion, high sample throughput and high performance. A large selection of high purity quartz and TFM inserts are available for these rotors to work with smaller sample amounts or to minimize the dilution factor of analytical solution.
Our microwave digestion systems can be used with a wide range of rotors and accessories providing a flexible, versatile and productive platform for digestion and extraction processes, microwave synthesis, protein hydrolysis and vacuum evaporation. For example, our selection of extraction rotor with flagship fastEX-24 with disposable vessels can extract up to 30 grams of sample with minimum solvent volume.

Product Specialist

Mikael Alfredsson

"Our expert in Digestion, Extraction, Syntesis and Evaporation with more than 20 years experience in the field of sales and service. Contact me for if you have questions or need a quotation"

This email address is being protected from spambots. You need JavaScript enabled to view it.
031-709 8186

SK-15 - easyTEMP


Regardless of the samples you’re trying to digest, the SK-15 High-pressure rotor is always an effective option to simplify your journey from sample to analysis, even with hard-to-digest samples, reactive samples or large sample masses. The SK-15 is a high-pressure and high-temperature rotor with a capacity of up to 15 PTFE-TFM vessels of 100 mL.

  • ● Unmatchable versatility

  • ● Large Sample Match

  • ● High Performance

MAXI-44 - easyTEMP


Many laboratories routinely process high number of samples, such as soils, sediments and aqueous samples. The MAXI-44, featuring up to 44 PTFE-TFM vessels of 100 ml, perfectly matches these requirements, providing high productivity, reliability and superior ease of use. The MAXI-44 finds its natural fit in all laboratories requiring to process large samples batches.

  • ● Digest Large Batches

  • ● Easy Handling

  • ● High Productivity

MAXI-24 HP - easyTEMP


The MAXI-24 High Performance (HP) and high throughput rotor was designed with double pressure limits and greater capacity than other high throughput rotors. It process increased volumes of sample and a wide variety of matrices within a single rotor-based platform. Quick-assembly vessels are closed with a simple hand-tightening, improving your daily productivity.

  • ● Greater Digestion Capacity

  • ● High Throughput for Several Applications

  • ● More Profitable Runs


With the comprehensive choice of rotors and accessories available, you can turn the ETHOS UP and ETHOS EASY into a versatile platform able to perform also solvent extraction, protein hydrolysis, vacuum evaporation and alkaline fusion.


The fastEX-24 rotor extracts up to 30 grams of sample with minimal solvent volume. It uses disposable glass vials, eliminating the need for cleaning and the possibility of memory effect between different runs. The 100 mL vials can accommodate the extraction of a large sample amount.


The high strength SK rotor body holds up to 12 digestion vessels made of high purity TFM. This rotor ensures complete digestion of any sample, including relatively difficult organic and inorganic refractory materials.


14-position rotor with 100 ml TFM medium pressure vessels. Vent-and-reseal technology. Contact-less temperature control in all vessels.


The MMR-15 can be used for vacuum assisted sample drying prior digestion, and solution concentration at the end of the decomposition process. The MMR-15 accommodates up to 15 TFM vessels of 100 mL. They are the same vessels used in the SK-15 digestion rotor, so no transfer of the solution is required when performing drying and concentration. Microwave modular rotor that takes advantage of the US patent 5,447,077.


The high strength SK rotor body holds up to 10 digestion vessels made of high purity TFM. This rotor ensures complete digestion of any sample, including relatively difficult organic and inorganic refractory materials.


High-temperature muffle furnace suitable for fusions, up to 1200°C. A variety of difficult samples, such as cements, ores, slag, sediments, soils, rocks, ceramics, pigments, and glasses, can be successfully prepared for XRF, AA and ICP analysis.

Utratrace inserts

This configuration reduces the amount of acid required for digestion to near stoichiometric quantities, which reduces the dilution factor and improve the detection limit.

  • ● Less acid volume

  • ● Higher sample amount

  • ● Lower dilution factor

  • ● Increased method detection limit

  • ● Less surface contamination

  • ● Lower analytical blank

Vessel Venting Technology

Patented "Vent-and-Reseal" Technology

All Milestone rotors feature an enhanced 'vent-and-reseal' technology for controlling the inner pressure of all vessels with complete safety. This patented (US Patent 5,270,010) technology provides the operator with unsurpassed safety and performance capabilities: highest temperature and pressure, highest safety standards, ease of use, and very fast cooling (180°C to 40°C in 10 minutes). While other systems use membranes or burst disks that render a vessel useless after venting, the Milestone system releases only the excess pressure from the vessel. This ensures that there is no stress to the door of the microwave system and no loss of sample as could happen in the

 case of a membrane or disk bursting. The illustration shows 'vent-and-reseal' in action: the vessel cap is held in place by a dome-shaped spring (1). In the case of over pressure due to a highly exothermic reaction, the spring is flattened, allowing the cap to lift up slightly (2) releasing excess pressure. Immediately the excess pressure is released, the spring reseals the vessel (3), and the digestion continues. There is no loss of sample and no clean up needed. The microwave program continues to completion and no re-run is required. While there are other methods of venting, only Milestone has 'vent-and-reseal' technology.

  • ● Superior performance

  • ● Higher safety and reliability

  • ● Low running costs

Self-regulated venting

The final method of venting is "self-regulating" and is used in the MAXI-44 rotor, and high-throughput rotors supplied by other manufacturers. These extreme throughput rotors were developed to address the needs of labs that process larger sample volumes on a routine basis. Self-regulating vessels are very easy to assemble/disassemble and rely on the Teflon

sealing plug inside the cap deforming to release pressure. Their compact design results in more moderate temperature and pressure capabilities, but allows for a large number of vessels to fit onto the rotor. These characteristics make self-regulating rotors ideal for easy to moderate applications such as clinical, environmental, food, etc. Most recently, some manufacturers have

applied the self-regulating approach to high pressure rotors designed specifically for more challenging sample types. Since self-regulating vessels are designed to vent, incomplete or unsatisfactory digestions may be observed given that the pressure loss does not allow the mandatory temperatures necessary for complete digestion to be achieved.

Other method of venting

There is another approach to venting, but it implies limitations compared to Milestone's Vent-and-Reseal and Self-regulating technology.

Burst disk

This method employs a simple burst disk in the cap which is designed to fail in an over pressure situation, instantly releasing all pressure in the vessel. When this happens, instantaneous boiling occurs, the sample contents are lost and the run has to be manually stopped. Significant clean up of the cavity is required, and corrosion of the cavity and internal components will occur. The

illustration compares the burst disk approach with 'vent-and-reseal': the red line shows the complete loss of pressure when a burst disk fails, and the whole run is stopped. The blue line shows what happens with Milestone's 'vent-and-reseal' technology: excess pressure is gently released at just over 30 bar, and the digestion continues to completion, with no loss of sample.

Subscribe to our newsletter:


At Kovalent we strive to establish and develop long-term partnerships with our customers. When we use the word “partnership” we mean that Kovalent becomes an integral part of our customers’ projects, where we are expected to fully understand their application needs. We aim to make Kovalent our customers’ first and natural choice, and this ambition permeates our entire organisation from initial contact to finished and delivered product.


Kovalent AB
Hulda Lindgrens gata 6A
Phone: +46(0)31-709 81 80
This email address is being protected from spambots. You need JavaScript enabled to view it.
Org.nr: 556417-2194


Genetec is a member of the same family of companies as Kovalent. Both companies share the same set of values and are in many ways integrated with each other. The main difference between the two companies are their products. Kovalent is involved in system solutions including instrumentation and Genetec is mainly working with consumables. The focus of Genetec is chromatography accessories. You are welcome to visit their state of the art web shop: genetec.se