COMPARISON OF MICROWAVE-ASSISTED AND CONVENTIONAL LEACHING USING EPA METHOD 3050B

A microwave-heated EPA method 3050B for the leaching of key elements ( cadmium, chromium, copper, lead, nickel, zinc) of environmental import ance was tested and compared to conventional hot plate-heated EPA meth od 3050B. All commercially available temperature and power-controlled atmospheric pressure microwave systems were used for the adaptation of EPA method 3050B. Three temperature feedback control systems were eva luated for regulating the temperature of the leachate including outsid e (IR sensors) and inside the sample flask (gas bulb thermometer). Res ults, which show the efficiency and effectiveness of the microwave sam ple preparation method, are discussed for the leaching of three NIST S tandard Reference Materials: 2704, 2710, and 2711, The elements were d etermined either using ICPMS, ET-AAS, or F-AAS. This study demonstrate s that microwave heating with enhanced reaction control leads to impro ved precision compared to conventional heating sources.