Where is microwave-based analytical equipment for solid sample pre-treatment going?

This article presents an overview of the different microwave-based devices used for solid sample pre-treatment. They comprise multi-mode and focused microwave devices, as well as closed and open systems. There is also a review of dynamic approaches based on the coupling of microwave-based devices to other steps of the analytical procedure, such as pre-concentration, chromatographic separation or detection, which allow total or partial automation of the whole analytical process. Special open systems, such as a microwave-ultrasound combined reactor, a focused microwave-assisted Soxhlet extractor, a microwave-assisted dryer and a microwave-assisted distiller are discussed. Finally, there is brief comment on microwave-assisted robotic methods, and the closed and open microwave systems are compared. (C) 2003 Published by Elsevier Science B.V.