ANALYSIS OF STANDARD REFERENCE MATERIALS FOLLOWING DIGESTION USING A MODIFIED APPLIANCE GRADE MICROWAVE-OVEN

Microwave digestion provides a rapid means of sample preparation in th e analytical laboratory. The major disadvantage of this method is the high cost of commercial microwave digestion systems. Modifications to the magnetron timing circuits of an appliance grade oven to make it su itable for sealed vessel microwave digestion are reported. The oven wa s modified without alteration to the irradiation cavity, and all initi al safety features remain intact. Following digestion with the modifie d oven, NIST Standard Reference Materials (SRMs) were analyzed by indu ctively coupled plasma emission spectroscopy. The analytical data are similar to the certified concentrations in the SRMs, indicating that t he modified oven provides a durable, rapid, cost-effective means of sa mple preparation. (C) 1996 American Institute of Physics.