Microwave-assisted extraction

Extracting compounds from various samples using traditional methods involves some give and take.

You can choose to use Soxhlet, which is relatively inexpensive for equipment but uses a tremendous amount of solvent and takes hours to run.

Sonication is fast, but it also requires copious amounts of solvent and banks of individual sonicators (which also adds to the cost) if your laboratory handles more than a few samples a day.

Pressurised solvent extraction uses much less solvent, but only processes six samples per hour and the equipment is costly.

A solution

Microwave extraction has been used for many years to extract compounds from plastics, biological samples, foods, animal feeds, paper, wastewater and many other types of samples. In early 2008, the US Environmental Protection Agency (USEPA) approved Method 3546 for microwave extraction of organic compounds from soils, sludges and sediments. It is a proven technique that is fast, uses significantly less solvent than traditional techniques and is cost effective.

With the capability to process 40 samples simultaneously and a technology that provides optimum control for high-pressure extractions, the MARSXpress (CEM Corporation) microwave reaction system provides a fast, reliable platform for busy analytical laboratories, allowing 80 extractions and filtrations to be performed in less than four hours. The system uses 90% less solvent than Soxhlet, making it a much more environmentally friendly technique.

The advanced technology of the system makes it remarkably easy to use. The infrared temperature sensors and the advanced design of the vessels allow the system to accurately measure the internal temperature of each vessel virtually instantaneously. The dual, NIST-traceable, calibrated temperature system provides control that users can rely on for the extraction results they need.

First, the sample is weighed into a patented MARSXpress vessel and solvent is added. Microwave extraction is much more efficient than other methods, so you use significantly less solvent than with other techniques.

The vessel is then capped and loaded into the carousel. The MARSXpress vessel features a simple screw-on cap and does not require the use of special tools. The carousel is then placed in the microwave, the appropriate method is loaded and the system is started. The MARSXpress comes with a pre-loaded library of USEPA-approved methods, though users can always program their own.

Finally, the ‘start’ button is pressed and the extractions are underway.

It’s that simple.

The SynergyPrep software displays and records temperature readings for all the vessels, so users will know for certain how well each sample performed. This is especially helpful when running samples from different sources on the same carousel.

Chemists in busy testing laboratories need accurate, dependable results in a timely manner. The MARSXpress system provides those results with a method that can help significantly reduce solvent usage and is also cost effective.

CEM products are distributed in Australia and New Zealand by DKSH Australia Pty Ltd.