Problem: Extracting compounds from various samples using tradition-al 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
lab handles more than a few samples a day. Pressurized solvent extrac-tion uses much less
solvent, but only processes six samples per hour and the equipment is costly.
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 U.S. 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 sol-vent than traditional techniques and is
cost-effective.